Archive of Our Own ^beta

Chapter Text

The modern world had been just the slightest bit dull to Gen. Sure, he was achieving his dreams - he had a book out, had a show. He was moving up in the world in his career of choice. He was young and cute, people thought he was witty, and it was nice to be so well thought of and liked.

But still. Dull.

Fame was hard to get, supposedly, but Gen knew how people worked. He knew what to say to get a network executive to think he was the next big thing, or get someone to sign him for a festival. He knew how to write a book that was engaging enough to get someone to pick it off the shelf at a bookstore, but clear and just appropriately dumbed down enough that people would read it and think they had learned something.

There wasn’t really any meaning or substance to him and his life in the modern age. He had decided to go for fame because he could. Gen’s bread and butter is psychology at its core - there is a difference between meaning and goals. In the old world, he was drifting, skimming across the surface of life like a waterbug.

The Stone World is something new, though. There’s suddenly something grander than himself to be a part of. Before, the core of his existence was him - what Gen wanted, what Gen could achieve. People had mostly been there to be used or seeking to use him. Despite his proficiencies in casting illusions, Gen had had none about his line of work. He was there to cast some pretty dreams, inspire a kid or two to pursue magic, and then retire as his star started to descend. There wasn’t really any depth to his existence - he had meant it when he had told Senku he was a shallow man. At the time, he was.

Now, though, Gen is woven into something greater. He’s a part of a resistance, a piece of a revival. Lives depend on him now. It’s more stressful than dealing with network ratings, but Gen finds that he wears responsibility gladly. Between the sessions of crueling labor, the dull, repetitive tasks, the quelling of unrest and the potential of violence, Gen finds meaning.

He wouldn’t go back to the old world now, even if he could, he thinks. He’s had a taste of having a purpose, in having connections. It makes his old existence seem even flatter than it had felt before.

And he wouldn’t have Senku.

Most people are slightly boring to Gen. The challenge is often getting them to dance to his preferred tune, but he often finds his interest waning once he’s figured out what rhythm they require. As his fame grew, he had people sliding up to him with intent in their eyes and duplicity on their tongues, which shut him down even more.

Some of this is because Gen never felt fully Japanese. He’s too ambitious and flamboyant for a society that’s leery of people sticking out in any way. He has always been curious and intelligent, but school never sat with him well. He jokes about harems, but fails to mention that ideally it would have both ladies and gents. He hasn’t spoken to his mother in years - another mark against him, in a society that stresses respect. When he went to the States for an intensive language and magic course for six months, Gen was somewhat envious about how upfront Americans could be. Sure, their health insurance sucked and he wasn’t sure he saw the point of the Midwest, but he saw couples of all genders and races walking hand in hand in New York with no commentary at all.

Well, that’s not true - he saw a drunk guy shout a slur at a couple of very cute lesbians, but a burly man with a beard and a My Little Pony tattoo had marched over, grabbed the guy, and slammed him into a brick wall, before pulling out the guy’s wallet from his pocket and walking off with it. The lesbians didn’t even look phased, like that happened every Tuesday. New York in the the early morning hours had been a fascinating experience.

Anyway. Gen found most people frustrating. He couldn’t connect to anyone in Japan - the politeness of society and the tightrope tension of his field meant it was somewhat impossible to be genuine with anyone. People who were direct with him often wanted his money or his fame, and there was no depth to those relationships either, even if their limits were more clear.

Waking up in the Stone World had felt like a continuation of the old world, in some ways. Gen would have to lie about who he was and what he was thinking to most people, like he did before. Instead of getting him canceled, screwing up in this world could get him killed. He supposed that at least that was something. It kept him on his toes. Gen loathed being bored.

Tsukasa had awoken him from stone and almost immediately dispatched him to discover what had happened to this Senku Ishigami, someone who clearly sparked a lot of very strong feelings in anyone remotely familiar with him. Gen feels like he barely had time to pull on a kimono. Tsukasa was somewhat indifferent to the how and why of the petrification, focusing mostly on what he felt it would do for them to be in this new world. He gave Gen a cursory explanation, with no embellishment on the details.

Gen had geared up for what he felt like was likely to be a nasty, brutal and short existence. The feeling was more prevalent as Tsukasa guided him through his Empire of Might to show him the miracle cave. Gen was listening with only part of an ear as Tsukasa narrated the tale of Senku Ishigami and his goal to revive all of humanity. For one, Tsukasa had already said Senku was dead, so Gen didn’t really see why all the backstory was necessary. For another, Gen felt like it was a better use of his time to catalogue the various poisons he remembered he could make with native plants for when this rough existence became unbearable.

He wished he had been listening when he saw the tree with numbers carved into it. April 1st, 5738.

Gen is many things. He’s manipulative. He prefers to playact at being shallow, because it’s easier than showing depth. He’s ambitious and willing to use people, a streak of cruelty to him that feels impossible to ignore. He chafes at conformity, even as he recognizes the value of collectivism in times of survival.

But - in his hearts of hearts that no one ever gets to see - he’s also a romantic. He believes in things like fate more than he wants to admit to. It meant something, it must, for Senku Ishigami to have revived on Gen’s birthday. Someone impossible, who had the foresight to track time across the eons, even while in stone. Gen wondered how he did it, hoped he wasn't dead.

Knew immediately that if Senku was alive, Gen would betray Tsukasa for him, no questions asked.

Tsukasa had turned around to take Gen back to his base and stock him up on supplies to venture out into the forest to find the village and see if they had Senku with them. In the space of him turning away, Gen traced his finger along the date, felt the rough edges of the wood, imagined someone young and alone, carving this into a tree to mark that they existed. There was something within him that he hadn’t felt in years, something warm like lights on Christmas, something sparkling like a freshly chilled cola.

Then he met Senku, found him whole and breathing and deeply sarcastic, caustic like a weak acid and as kind as a freshly warmed blanket pulled out of the dryer. Senku fed him terribly bitter ramen and forced him to work at that grueling furnace, then asked about his friends with carefully concealed concern and showed him a light in the darkness when Gen was sure all he would have from here on out to see by at night would be the moon and a fire.

Senku defied the odds with a smirk, impossible with his greenish hair and his red eyes and his physical frailty that was still somehow so resilient.

Like Gen suspected at the tree, there’s no questions asked. He pretends for it to be in doubt, but he knows.

In this mad world, being by Senku’s side is the only choice Gen could ever make.

—

Gen’s hands are shaking when he sees Kohaku dragging Homura behind her while Ukyo is leading Hyoga, whose wrists are bound together with rope. Magma and Nikki are supporting Tsukasa, who looks like he’s hanging on by a thread, his chest soaked in blood and sweat beading his hairline. It’s barely dawn. Gen hasn’t slept all night. He wasn’t there to watch Senku fall over a cliff, unbalanced by Tsukasa’s weight and Hyoga’s shove.

In some ways, that’s worse than seeing it. He’s been consumed with images of Senku’s brilliant head cracking open like an egg, Hyoga’s spear slicing through his throat and silencing him forever. He’s not sure how strong Senku is at swimming, but he’s so physically unskilled overall that Gen can’t imagine he’s particularly good at it.

Gen acknowledges the stone world is dangerous. They barely have medicine. Wild beasts roam the land. Heaven forbid someone get pregnant, because childbirth might be a death sentence.

All that aside, Senku keeps getting fairly close to death, which Gen finds deeply unsettling. He tells himself it's a practical concern. Senku carries the burden of knowledge of all of human science. Gen, although he is inspired by the meaning this world has thrust upon him, wants some of the comforts of modernity back. He wants cola and soft pillows, ramen not made with foxtail and AC in the summer.

He’s damn well aware that’s not all he wants, but one thing the Stone World is teaching him is that reality is now often not about what Gen wants.

He tucks his hands into his sleeves to hide how much they’re trembling, staring at the depths of the forest where his friends are emerging.

Senku limps into camp, his face tense with determination and pain, his skin ashy under the streaks of blood and sweat on his cheeks. Kinro is awkwardly following him, looking like he’s been arguing with Senku the whole way back about whether he needs to be carried or not. Senku’s labcoat and undershirt are ripped, the bandages he usually wears around his forearms unraveled. One of them looks like it’s wrapped around his hand, the edges soaked red with blood. The other one must have been used on Tsukasa to bind the spear injury.

Gen breathes out unsteadily. He’s not sure Senku walking on his own means much - Senku had marched off into the woods by himself to befriend a dangerous stranger who he was aware was armed right after having his neck snapped and being brought back to life. But he’s alive and breathing, and Hyoga is as contained as he reasonably can be.

Senku spots him, and gives him a tight smile. He looks somewhat overwhelmed, like the adrenaline rush is beginning to fade. Gen takes that as his cue. He straightens his shoulders, plasters on a smile, and meanders over.

“Oh Kinro, I’m so glad you’re alrightyay!” he warbles, getting slightly in between Kinro and Senku. Kinro has never really known what to do with Gen - he’s much too straightforward to deal with him. So he nods, hesitantly, like he’s unsure if Gen will curse him. “What a hard day you’ve had, dealing with that astynay Hyoga,” Gen sighs, sliding in between Kinro and Senku a bit more firmly. “You should go help Ukyo secure the prisoners and then rest, rest! I’ll take care of Senku from here!”

Kinro looks somewhat concerned still - Kohaku probably told him to not let Senku out of his sight. “But Gen, I must -”

“Kinro,” Gen interrupts firmly, still smiling. “Go rest. I can handle this.”

Kinro purses his lips, but nods and trudges off after Ukyo. Gen waits until he’s fully gone to turn to Senku.

Senlu is watching him, dark red eyes vivid in the moonlight. He looks exhausted, but there’s still the echo of his usual smirk on his face. This close, Gen can see something dark wrapped around his chest. Senku’s impossibly upright hair is wilting. He looks like he desperately needs to lay down.

“Given everything that happened today, I got the supplies all moved into one of the caves and set up some guards for it,” Gen says. His throat feels dry. “I figured you might want a tent for yourself tonight. No need to share with Chrome.”

Senku chuckles. His voice sounds wheezy, like he can’t take a full breath. “He’s a clinger. Gross.”

Gen leads Senku towards a tent strategically placed by the warriors’ corner. Kohaku will be one tent over in case something goes wrong, easily backed up by Nikki. Inside, Gen has already set up a light with one of the batteries. The light isn’t one of the better ones - it’s naturally fairly dim, but it’s enough to see how Senku’s shoulders relax as the curtain falls into place behind him.

Senku slumps down onto the bedroll Gen had laid out earlier, huffing in a way that could be a sound of irritation, could be one of pain. Gen kneels in front of him, still with his hands tucked into his sleeves. He can’t stop shaking. He can’t stop staring at Senku, who looks pale and exhausted in the dim light.

Senku gives him a wry look. “You don’t need to hover, mentalist. I’m not going to keel over,” he says. His voice is still tight.

“Right, well, sue me for worrying.” Gen is disappointed to find he sounds more serious than he meant to. He wanted his words to come out airily. Instead he sounds as concerned as he feels. Senku has that impact on him - Gen finds it impossible to be less than truthful with him. “What’s on your chest?”

Senku’s smirk softens into almost a smile. For a moment, he looks almost as gentle as Gen knows him to be. “You saved me tonight, Gen,” he says.

Gen raises an eyebrow. He’s so thankful he’s not the type to blush easily. He can feel warmth threatening his cheeks, but he swallows it down. “And how did I do that?”

“I took a page out of your book - and some of those magnesium batteries you made.” Senku wiggles at the edge of his ripped coat, struggling to show Gen something under his shirt. “I wrapped batteries around me,” he explains. Gen reaches out, and gently pulls at the edge of the fabric to see the batteries nestled against his chest. “It stopped Hyoga’s spear.”

Gen inhales sharply, feeling his anxiety spike. He had heard Tsukasa was stabbed, but he was trying hard to pretend something like that wouldn’t happen to Senku. It didn’t, but the closeness to the act is terrifying.

Senku notices, because of course he does. There’s no way not to, with how close together they are. “I had sensed that the vibes were ten billion percent off with Hyoga,” he says tiredly. “I wrapped the batteries around myself earlier, before the explosion. It stopped his spear dead.” He winces. “My chest is bruised to hell though.”

“Let’s get it off you, then,” Gen says. Words cannot express how grateful he is that his voice comes out steady. He helps Senku shrug out of his shirt and unwrap the batteries from his chest, leaving Senku bare. There’s a truly magnificent bruise blooming on his chest, splotchy purple edged with yellow. Gen has no idea how Senku survived this, it should have cracked some ribs.

Senku is bizarre, a walking contraction in strength. Any muscular definition he has is largely the result of the fact he barely remembers to eat. He comes off as oddly fragile for someone who likes to forge things and rebuild industry from the ground up. Yet he’s also incredibly durable. He survived by himself for six months, picked himself up after having his neck snapped, and had been willing to physically throw himself at Homura. He stayed lucid through thousands of years trapped in stone, and immediately plunged deep into the work of reviving everyone without hesitation, hardly faltering even when he learned all his work would never bring his dad back. Gen has met a thousand people who claim to be strong, but they have nothing on Senku.

“I found all the herbs to make yokukansan,” Gen says to distract himself. “Do you want some? It might help with the pain.”

Senku smiles grimly. “Anything would help at this point,” he admits. “Your horticulture experience is helpful here.”

“And here I thought you would consider Kampo to be bullshit,” Gen says, pulling a packet of herbs from his sleeve and opening it carefully before passing it to Senku. “Here. Chew them thoroughly. I’m not sure if heating them in a tea would counteract some of their benefits.”

“I don’t think Kampo is bullshit,” Senku says, carefully pouring the herbs into his mouth. “At the very least, it can trigger a placebo effect, which would help me right now. We don’t quite have the ability to make things like ibuprofen just yet.” He starts chewing and grimaces. “Ugh. We have to find some way of making this palatable though.”

“I’ll play around with it tomorrow,” Gen says, stacking the batteries to the side. Senku will probably make him recycle them first chance he gets, repurpose the materials into something new. “I’m assuming Tsukasa will need some himself.”

Senku’s drawn face tightens, and he looks down. “Ten billion percent,” he says quietly. There’s an edge of something to his voice.

It’s entirely irrational, but Gen feels a flash of jealousy. He wonders if this is how Senku reacted when Magma almost killed him. Senku had cared for him, because Senku is fundamentally a good person, but Gen, selfishly, wants more than just his care. He wants his worry, wants his empathy. He wants Senku to fret at the idea of him being injured the way Gen does for him. It’s frustrating to see this offered to someone who killed Senku to further his ends and wonder if he, someone whose existence was restructured around one person, was offered the same depth of genuine compassion.

He pushes the feeling aside. It’s petty. It won’t help Senku or Tsukasa right now. “We’ll figure this out, Senku-chan,” he says instead. “You’re clever and Tsukasa is strong - and he just got Mirai back. He’s not going to let this be the end of him.”

Senku’s lips thin. “It almost was, though,” he replies, sounding distant, lost in thought. “Hyoga’s spear went straight through him, and he had to then beat him off to give me the time and space to devise my impromptu taser. That’s just going to accelerate his bloodloss.” He looks like his brain is going ten billion miles an hour, consuming every remaining shred of energy he might have.

Gen, hesitantly, reaches forward and covers Senku’s hand with his own. His skin is dry and cool. Senku’s eyebrows draw together as Gen squeezes his hand gently, and slowly lifts his head to meet Gen’s eyes. His red eyes are red-rimmed, the bags underneath them dark and unyielding. Gen’s heart is racing, and he briefly hopes Senku can’t feel how it jackrabbits his pulse. “You need to sleep,” he says. “Even if just for a few hours. You can’t deal with this puzzle if you’re running on fumes.”

Senku heaves a sigh and presses his bandage-wrapped hand against his face. Gen’s eyes catch on the blood staining his pinky. “I know.”

“I’ll give Tsukasa some yokukansan,” Gen promises. “I’ll also start collecting blood type information from all the modern day people. I already know Tsukasa’s blood type.”

“Why on earth do you know that?” Senku asks tiredly, not fighting back as Gen gently forces him to lay down.

“When he was backstage for my show, it came up,” Gen says. “I was looking into ketsueki-gata at the time, and he was, well…kind of intimidating.”

Senku wrinkles his nose. “Ugh, that pseudo-scientific bullshit,” he scoffs, disgusted. Gen giggles, a bit frantically. He’s feeling slightly punch-drunk. The anxiety, the lack of sleep, the stress of winning the war and then almost losing Senku - it’s getting to him. It’s hard to watch his mouth, but he has to.

“Almost all personality tests are bullshit outside of the Big Five assessment,” he agrees, and Senku snorts. It always delights Gen to get a genuine reaction out of him. “But it was a light and easy conversation topic and something useful to get a grip on Tsukasa himself while we were waiting to go live.”

“How so?” Senku asks as Gen gently draws the blanket up. He sounds like he’s crashing. His assured voice is slurred.

“Well, if someone reacts like you just did, I know I’ll have to probably talk about how absolutely invalid the Myers-Briggs is,” Gen says drily. “Personality tests and stuff like horoscopes can be useful for introspection, if people are aware of their limitations. But often people either aren’t aware of that, or they want to be fully dismissive of the value they can provide.”

“How did Tsukasa react?”

Gen shrugs. “He didn’t seem impressed. I got his blood type out of him and then started nattering about how I could totally tell his bloodtype was B because of how passionate he is. I think he thought I was vapid. To be fair, I was at the time.”

“Hm.” Senku’s eyes are drifting shut. He looks like he’s slow-blinking at a cat. “I suppose like with many things, your supposed vapidity is working to our advantage here.” He yawns widely. “Let me know what you find out on bloodtypes,” he mumbles, slumping into his blanket. “I’ll probably have to get going on a transfusion when I get up. Also can you get Kaseki and Chrome on making some surgical tools? I’ll probably need some needles and the setup for an IV, and-”

“Senku. Stop.” Gen covers Senku’s hand with his own again. Senku blinks up at him sleepily, and Gen’s heart aches in his chest. He wishes Senku didn’t have the weight of the world on his shoulders. He’s thankful Senku made him a better person. He knows there’s no other way they could have been like this in their lifetime if the petrification hadn’t happened. “You need to sleep. You can’t help him if you’re exhausted.”

Senku stares at him for another long second in his quiet, assessing way. Gen wonders what he notices, if he can see through all the rot and grime inherent to Gen’s soul, to the garden that Senku sparked within him with his hope and passion and curiosity towards life. If Senku is aware that before Gen had met him, life had been a chore to get through rather than an experience to treasure.

Senku’s lips quirk into his signature smirk. Gen has to swallow around the dryness in his throat. “Don’t let this go to your head, mentalist,” he warns. “Just ‘cause I’m listening this once doesn’t mean you’re right.”

“Wouldn’t dream of it,” Gen replies, and Senku settles his eyes and worms into his blanket without another word. He doesn’t drop Gen’s hand as he drifts off to sleep. Gen isn’t sure what to make of that - if Senku just forgot to let go, or if he needs the comfort of someone not trying to kill him and just being there.

Senku doesn’t usually like to be touched much. He’ll high-five someone, but shy away from a hug. Taiju had tried to envelop him in an embrace, and although it was apparent Senku deeply cares for him, it was side-stepped. To sit here quietly as Senku drifts into sleep, their hands tangled together, is an honor Gen never expected to be offered.

He can feel the chasm of everything he wants and feels incapable of ever getting yawning within him, threatening to swallow him whole. He had gone to a planetarium showing in the States one time and opted for the show about black holes. It had talked about how if you were falling into one, you would be pulled apart, atom by atom. Gravity at your feet would be different than your head, and you would unravel down to your core.

Outside of the event horizon, time would appear to slow, so to an observer you would always be falling into the depths, even as you were ripped apart.

Gen wishes someone had warned him that that’s what Senku’s attention is like.

He’s been aware he’s been in denial. It was useful during the lead-up to the war, easy to fixate on Senku’s flaws when he’s being forced to build hundreds of batteries and sleeping in an uninsulated hut. He had been unsure if they would survive, despite the confidence Senku projected.

But here, in the quiet of the tent with just the hint of birds greeting the dawn, holding Senku’s hand and listening to his quiet snores, Gen lets himself be honest for once in his life.

Here, past the end of the world, so far into the future that not even the dust of humanity remains, Gen has found someone who inspires a love in him so deep and profound that for the first time in his life, Gen wants to actually live, and not just drift. In the hardest conditions he’s ever faced, Gen has finally found a reason to keep breathing, to open his heart, to care.

Senku’s breathing is deep and even, his snores just the right amount of breathy to be cute moreso than irritating. He looks young without the weight of his thoughts on him. Gen inhales shakily, and uses the hand not trapped in Senku’s weak grip to trace the edge of his cheek.

Gen is more pragmatic than people give him credit for, wise enough to know that a good way to avoid misadventures is to keep your mouth shut. But he’s also a romantic and a dreamer, and so he can’t quite begrudge himself from whispering as quietly as he can, “I love you, Senku. I’m so glad you’re alright.”

He needs to go. Tsukasa needs what painkillers Gen can offer. Gen needs to tell Kaseki what an IV drip is. He has to find the matching blood type for Tsukasa.

But fundamentally, Gen is selfish, and his world is shifting on its axis. In the face of an earth-shattering revelation, it would be irresponsible to not take a moment to reflect. So he allows himself to sit quietly, holding Senku’s hand, and lets himself love.

Chapter Text

Gen settles down at the edge of the cliff with a sigh to watch the sunset. He’s feeling tense, unnerved. The fact that they just recently consigned Tsukasa to cold sleep would account for that, but Gen’s dismayed to find that his reasoning feels pettier than that.

Tsukasa is just pretty, and as sharp as the spear that pierced him. He's got long eyelashes and incredible hair, and a body to inspire the gods. There's a delicate curve to his face, and a sharp mind beneath it all. Tsukasa likes video games and thinks about his own philosophy of life, had been willing to spend his life working in service of a sister he wasn’t sure if he would ever speak to again. He faced down his death and uncertain revival calmly, looking Senku in the face as he said he only wants Senku to be the end of him.

Gen is fairly sure looks aren’t a thing Senku notices, but he does notice attributes like determination, curiosity, and selflessness. Much like luscious locks, Tsukasa has those in spades.

Gen had been hovering just outside the cave while Senku prepared the refrigerator for Tsukasa’s cold sleep, listening in on their last conversation. He heard the crack in Senku’s voice when he realized Tsukasa had fallen silent, and then the rough, wet inhale. Senku had been suspiciously quiet for a few moments before he called for Taiji, Kohaku, and Nikki to help move Tsukasa into his frozen coffin. Gen slipped away before he could be noticed. This didn’t feel like a time for him.

That was yesterday. Senku spent most of the day today drawing up plans for their next project - a ship, big enough to take them to the new world, he had told Gen when Gen brought him breakfast. Then he went off in the afternoon to check the performance of Tsukasa’s cold coffin, that oddly distant look back on his face. Gen spent the day feeling somewhat relieved by how busy Senku is. He needed the space to process how he’s feeling, prod at the mass of anxiety within him.

Insecurity is new for Gen, and he’s not quite sure how to navigate it. Senku has his uses for him, sure, but Gen is also deeply aware that if they had met in the old world, chances are better that Senku would haven’t given him a second thought. Gen, then, had been a trashy mentalist - someone with skills and smarts and capabilities, taking the easy path out and coasting through life.

He doubts Senku would have been much impressed by him then - Senku has already been clear he thought Gen’s book was full of shit. To be fair, it was - no one was really all that interested in what Gen actually knew, just in trashy secrets behind his illusions. Senku had taught himself physics and chemistry, learned English to email NASA scientists, went to Africa to try to treat ebola. Senku has always been confident in his abilities and driven to learn more, do more - to see the world and solve some problems along the way.

Tsukasa might be a better fit for him, once they manage to revive him, Gen reflects bitterly. Tsukasa is intelligent, driven, charismatic, thoughtful, strategic - an excellent match to Senku himself. What could Gen offer that Tsukasa can’t? Only negatives.

Gen draws his knees up to his chest, wraps his arms around them, and sighs. It’s too warm to feel cold like he does. He wishes the skies would have the dignity to be cloudy - it’s almost impossible to get a good sulk going in full sunshine.

He’s just out of sight of the camp they’ve been setting up in the remains of the Empire of Might. People are chattering down below, working on getting dinner started and beginning to gather materials for the watchtower Senku announced they’ll be building. He can hear Kohaku arguing with Ginro about whether they need to keep training. The light is soft and golden, and in the distance, Gen can see the sparkling sea.

In the old world, Gen rarely took the time to sit and just be. He shuts his eyes and listens to the noises of their new society, the birds chirping. Smells the roasting meat and tang of the ocean. For a moment, he lets his mind just drift, temporarily free of all the stress and anxiety that has been imposed upon him.

“Where do you think all of Tsukasa’s guys got their hair done?” he hears a voice behind him ask. He turns slightly, and sees Senku walking over to him. He’s smirking as he settles down next to Gen, looking out over the view. He looks less exhausted than he did the night Tsukasa was stabbed, but Gen can see the edges of his still-healing bruise through the gaps of his labcoat.

“What?”

“Some of Tsukasa’s guys have hairstyles like they went to a stylist and asked for the latest in cavemen trends,” Senku clarifies without looking at him. “Do you think that’s what they looked like back in the modern day?”

“Oh god,” Gen groans, picturing it. “Tsukasa mostly was picking guys he knew from his MMA circuit and the martial arts community. I can’t imagine fighting with like…a shaved head and dual pigtails.”

“Seems like a bit of a convenient handle,” Senku snorts, grinning, tilting his head to look at Gen. His eyes glitter like freshly unearthed rubies in the light of the setting sun. “Funnier still to imagine how they cut it when they woke up.”

Gen wrinkles his nose. “They have some sharp-ish stone blades. They found some obsidian and used that, primarily, but there really isn’t much precision in that, not with how they were refining them,” he says. “And then they woke up Ukyo and he needed so many sharp rocks for his arrows. So I’m not sure how they’ve been handling hair.”

“I presume it’s rude as hell to ask why their hair looks dumb as shit, so I guess we’ll never know why they look like that for sure,” Senku says seriously.

“Bingo. Look at you, learning about how to have some polite human interaction,” Gen replies cheekily, which makes Senku snort.

In moments like this, being with Senku is the easiest thing in the world - easier than breathing. Gen appreciates his bluntness, finds his sense of humor hilarious. Despite his crassness, even though he’s as direct as a headshot and ruthless to boot, Senku is engaging and funny and by and large kind. Gen can’t think of anyone he’s ever been at more ease around. He never has to worry that Senku is lying to him - Senku doesn’t see the point in being subtle. He’s upfront with who is and what he wants to be doing.

“Is there something you need, Senku-chan?” Gen asks after a long moment. Senku must need something if he’s come up all the way here to find Gen. He had mentioned needing to get people on board with the ship plans - potentially he’s here about that.

Senku is silent for a beat. “Don’t get irritating about it, mentalist, but I just needed a break from Chrome,” he says finally. “I’ve had to explain basically all of HVAC to him today. Heat pumps are fascinating, just ten billion percent not useful right now for what we have to get moving on.”

“The ship, right.”

“Sure,” Senku says. “The ship.” Gen glances at him. Senku is squinting into the distance, looking tired and thoughtful. Like this, Gen can imagine what it could have been like, if they knew each other in the modern day. What it would feel like to sit on the roof of a building, watch the sun set over Tokyo. How it could feel, to walk Senku to his train and text him goodnight.

“Is there something else going on?” Gen asks carefully. He wonders if it’s about Tsukasa. There were clearly some strong connection between the two of them, and Senku essentially had to kill him yesterday. Senku doesn’t always seem like he knows how to talk about how he’s feeling. Gen wonders if he feels like he can at all.

“Don’t be doing that mentalism shit on me right now,” Senku says without looking at him. There’s no bite to it, but Gen, oddly, still feels a little stung. “Maybe I just wanted to talk about some weird hair with you.”

It feels a little bit too close to his conversation with Tsukasa yesterday for Gen to be comfortable. The talk of who Tsukasa would take to the moon, or how Mario is clearly tripping balls - Gen took that as a confirmation that Senku and Tsukasa would have always had a connection, no matter the time they found themselves in. Tsukasa would have been the one chatting with Senku on a roof or waiting with him for a train, talking about video game theories and if they would ever realize their modern-day dreams.

Gen doesn’t get that. He only gets to be by Senku here, in the wreckage of the world. Senku would have never found a place for him in the modern day. Gen’s use is to corral people into the ends Senku has in mind, to bounce ideas off of, to back him up.

Gen said he would descend into hell for this man, to achieve what he wants. He meant that. He shouldn’t be fixated on what-ifs. Gen is trained in human irrationality - he would truly be a fuckup if he couldn’t recognize it in himself.

“Well I’m honored I get to hear what Senku-chan thinks is fashionable,” he chooses to say. He knows what Senku needs from him now - a distraction. “I always take my styling advice from men with unconventional hair.”

“Ugh, should have figured that would be the angle you’d go with,” Senku grumbles without any heat. “At least I’m not mostly shaved with two braided pigtails.”

“I think you could pull off pigtails, at least,” Gen says cheerfully. “It’s a new world, Senku-chan. There’s no rules for us anymore. We make them now.”

Senku glances at him, his smile a touch more gentle and less sharp than it usually is. “We’ve gotten this far,” he says, and it sounds like a promise. The moment suddenly seems charged, like the air before a lightning strike. It feels like every romantic moment in a movie - they’ve won the war, they’re working for their dreams, and here they are, overlooking the ocean with the setting sun making Senku look impossibly gentle.

Gen panics slightly. This is a bit too much, days after Senku risked his life to save another man and Gen let himself acknowledge his feelings.

He jumps to his feet, feeling a bit too unsteady to be reasonably this near a cliff. Senku looks a little startled, eyebrows drawn together. “Well thank you for the lovely atchay, Senku-chan, but I just remembered I promised to show Ruri how to make paper!” he says, clapping his hands together. He had promised that, actually, but there’s no reason to do it now as the sun is setting. All good lies have some sprinkles of the truth, however, and this is what Gen has. “Anyway, I will see you at innerday!”

He turns to flee before Senku can get up to join him, feeling more like a coward than he normally does. As he goes, he can hear Senku say softly, “See you,” as if he has no hope of a response.

—

“Are you going to tell him how you’re feeling?” Ruri asks. They’re in the middle of jarring fruit preserves for the eventual voyage across the sea and to keep the villagers healthy during winter. It’s repetitive, which is good, because Gen is slightly too preoccupied to do anything more complicated. But it’s also bad, because now he’s ruminating.

“If the observatory didn’t tip him off, I don’t know what will,” Gen grumbles sourly, slamming the scoop of fruit jelly into the jar with more force than it really needs. Ruri had asked what was going on with him, so kindly and gently that not answering didn’t feel like an option.

Gen didn’t think he could fully explain the complicated mass of ugly feelings within him, so he went with the easiest version - he’s in love with Senku and pretty damn sure it’s not reciprocated. It doesn’t quite cover everything eating at him, but the confession of any sort of romantic feelings is enough to distract Ruri from prying at anything deeper.

Ruri giggles. “Senku is a genius with an incredible memory and a kind heart,” she says. “But an emotion could smack him in the face and tell him exactly what it is and he still would be confused.”

Gen doesn’t reply, just shoves his jar over to the side with all the other filled jars, waiting to be vacuum-sealed. To be fair, he hadn’t been fully aware of what it was that burned within him when he gave Senku that observatory. Gen is so used to approaching people with just the surface of him showing that he’s forgotten how to be himself, fully and unashamed.

Ruri gets it, which is why he likes her so much. Being the priestess has meant that that aspect of her always comes first, and being Ruri second.

“I don’t think it’s healthy to keep this to yourself,” Ruri says after another moment. “And Senku is far from the nicest person, but he is kind. He won’t judge or hate you, Gen. He forgave Tsukasa for killing him - his heart is endless.”

“Should I be worried you’re gunning for my job, Ruri-chan?” Gen asks lightly in the hopes of distracting her. “Look at you engaging in this psychological reading.”

Ruri laughs lightly. “I have my own skills, you know,” she says, wiping her hands on a rag and standing up to take the jars over to Kaseki for processing. “Maybe not to your level, but people do look to the priestess for wisdom and guidance. I did have to be capable of offering it.”

“I’m sure you’re brilliant at it,” Gen says, and is slightly annoyed to find he means it. He’s used to flattery being a tool he employs to get what he wants. It’s almost frustrating to find he means it when he compliments these friends he has now, that he would have never met if the world hadn’t fallen apart.

“So then listen to me when I say Senku values you and respects your opinion,” Ruri says, looking at him pointedly. “He doesn’t entertain people wasting his time, but he always has time for you. I think it means something, Gen, even if you don’t.”

It’s melodramatic, but no one ever accused Gen of being level-headed. He lets out an exaggerated groan and slumps in his chair, then allows himself to lean sideways until he flops bonelessly to the floor.

“Thank you for the opinion, Ruri-chan, don’t mind if I just ignore it,” he mutters into the dirt. Ruri probably can’t hear him over how hard she’s laughing.

“What the fuck is wrong with the mentalist?” he hears Senku say and he bolts upright, suddenly feeling like a toddler throwing a tantrum. He forgot they’re by the edge of the camp and people can see him losing his mind. “Oi, mentalist, why the fuck are you on the ground?”

“Is this a normal modern-person reaction to sharing gossip?” Ruri asks, sounding intrigued.

“No, the mentalist is just weird. Wait, gossip?”

“Gossip is the foundation of all social bonds, Senku-chan,” Gen interjects, trying his best to get to his feet gracefully. He’s got dirt all down his side now - it’s not like he can really ever be clean, but Gen still has modern proclivities and reactions, and something just doesn’t sit right being grimy in front of someone he desperately wants to love him back.

“Gross,” Senku says, although he sounds less disgusted than Gen expected him to be. “Come on, mentalist. We’re going captain-hunting and I want your take.”

Ruri is grabbing the basket full of jars they filled and she catches Gen’s eye over Senku’s shoulder on her way out. Tell him, she mouths and Gen shakes his head on instinct.

Senku’s eyes narrow. “What? A personnel-related issue you don’t have an opinion about?”

Shit. Gen doesn’t particularly want to tell him he was trying to get Ruri to leave him alone. Senku doesn’t always follow the social conventions Gen expects, but humans inherently need to pick at things they think there is information being kept from them.

“I promised dear Ukyo I would help with reading class for the children today,” he says, grasping for an excuse. Ukyo, now that they’re in a less testosterone-fueled environment than the Empire of Might, has proven to be sharp, kind, and - useful for Gen’s purposes - willing to be somewhat malleable when Gen needs him to be. He’s sure Ukyo won’t counter his lie if Gen asks really nicely.

Senku’s lip thin and he crosses his arms across his chest. “The captain is going to be a pretty key fucking figure for us, mentalist. You’re the one worried about social cohesion.”

“I assume you’ve already asked the lovely Minami-chan for her recommendations, so I fail to see what insights I would offer that she wouldn’t,” Gen says, aiming for cheerful and sounding a little too airy for it to be genuine. Senku seems to pick up on that. There’s a tightness to how he’s holding his jaw.

“You can’t complain then about who I end up going with,” he warns. “I might pick a real asshole.”

“I trust you to make whatever decision you think is best, Senku-chan.” Unfortunately, Gen does mean this. Senku is strong-willed, willing to go against convention to achieve his ends. He’s also sure Minami won’t present Senku with any real jackasses.

Senku still doesn’t look happy. He nods jerkily, and then waves Gen off dismissively. “I’ll see you later then,” he says, sounding frustrated.

“Bye, Senku-chan! Don’t have too much unfay without me!” Gen keeps his head held high as he marches across camp to where Ukyo is setting up for class. He doesn't allow himself to turn and look at Senku, doesn’t let himself wonder what he would see on his face.

Ukyo raises an eyebrow as Gen draws near, but kindly pitches his voice low. “Embarrassing performance for such an accomplished liar,” he murmurs playfully. “But don’t worry, I won’t tell Senku.”

“Of course you heard all that,” Gen grumbles sourly. He’s not used to having people to confide in. If Ruri and Ukyo weren’t so upstanding and deeply unlikely to spread what he’d like to keep private around, he thinks he would be more upset.

It’s an odd thing - having people to love, people to trust.

Ukyo laughs quietly. “We’ve all got our issues,” he says. “You’ve been kind enough to humor mine. Anyway, I’m going to set you up with a group of the kids that seem to be doing a bit better than the others. Suika’s really picking up on reading quick - Kinro might join today as well since Kohaku is going off with Senku to get a captain.”

He starts setting Gen up with a slate and some chalk at a separate table. Gen can’t help but glance after Senku as he listens to Ukyo explaining what he has planned for the more advanced readers. Senku’s collecting Kohaku and Nikki for the expedition he has planned, explaining something as he leads them towards the beach.

Gen wishes, briefly, that he was less of a coward. That he could be direct, like how Senku is, and be with him right now. Wonders if he’ll ever feel like he deserves to be.

Before he vanishes down the hill, Senku catches his eye. His disgruntled expression briefly slips and he offers Gen a slight smile and a two fingered salute, before turning around to walk away.

Chapter Text

Gen enters the lab hesitantly, holding the dinner plate out as both a shield and an offering. Senku has been consumed in balloon-building and oil location for the last two days and Gen has barely seen him, outside of Yuzuriha’s fashion show. Some of this he attributes to the explosive, driving energy Ryusui brought with him when they broke him out of the stone. Ryusui is go-go-go, high-key and relentless, so alight with the fires of what drives him that he can’t help but set those near him aflame alongside himself.

Senku brings his own determination to things, but he’s definitely pushed by people who are burning with passion like Ryusui. Ryusui wants things like ships and haute couture, fine dining and airplanes, and Senku seems willing to be pushed into what they can bring into this new world of theirs.

Gen often feels like he’s just keeping up with where Senku’s brilliant mind is taking him when it comes to what to build next. He’s been surprised by literally everything Senku has thought of creating, from cell phones to tanks to a car. Ryusui doesn’t seem shocked at all - worse still, he eggs Senku on, pushing him further and farther.

He’s barely resolved his insecurity from Tsukasa, and he vaguely knew him. Gen has no idea how to approach the anxiety Ryusui sparks in him regarding his and Senku’s relationship.

Senku doesn’t even look up as he enters, scribbling away madly at his blueprint, and Gen swallows. “Are you usybay, Senku-chan?”

Senku starts and looks up like he’s coming out of a fog. It takes a second for his eyes to focus on Gen. “Oh.” He drops his charcoal. “Mentalist. What is it?”

Gen wordlessly holds up the plate of food - roasted fish and some root vegetables. Nothing fancy, but he doesn’t think Senku has eaten today. “Snagged the last plate before Magma could down it all.”

“Put it down wherever there’s space,” Senku says, waving his hand dismissively. Gen puts the plate down at the edge of the table carefully, sliding it among the detritus of Senku’s overworked brain - his blueprints, the snapped charcoal sticks, the half drunk cups of tea.

“How’s it going?” he asks, tucking his hands into his sleeves.

Senku groans, scrubbing at his eyes with the back of his hand. Charcoal is streaked across his cheeks like warpaint. “Frustrating,” he grumbles. “We’re still having issues finding oil and now we have to remap the whole damn coastline since Fuji’s eruptions probably changed it pretty drastically.” He sighs heavily and stands to stretch his arms over his head. “It’s reminding me of when I hadn’t realized the constellations had moved since we were petrified,” he says, more to himself than to Gen. “Makes me wonder what other things I’m missing.”

Gen hums, searching for the right thing to say. Senku can be difficult to comfort or support. He dislikes overt sentiment, responds best to sarcasm and teasing. It’s not to say he doesn’t feel - he does, and deeply. But he shies away from it, even in moments where vulnerability is to be expected. “I’m sure you’re doing your best,” he settles on finally.

“My best isn’t good enough if I can’t find the damn oil,” Senku says sharply. “Everything is riding on it now.”

“It’s an insanely complicated problem,” Gen agrees serenely, trying not to sound irritated with Senku’s tone. He adjusts one of the papers on the table that’s close to the edge. “We have a lot of smart and capable people here to work with you on it.”

“Ukyo, Kohaku and Chrome can’t even start exploring without an idea of where to go,” Senku argues. “We’ve got people, but they’re waiting on me to solve this damn issue.”

Gen inhales slowly. Senku has the weight of the world on his shoulders, and it clearly bothers him when he fails to anticipate that something might have shifted since the modern day. Gen can’t necessarily fault him for getting snappish sometimes, although he wishes Senku would learn Gen isn’t always trying to provoke him.

“Eating might help. Give your brain a break,” he says gently. “Rest can help drive inspiration. It was a whole field of study in the modern day. Sometimes your mind just needs to simmer on something.”

“I have been simmering!” Senku snaps, crossing his arms across his chest. “We’ve been out at all hours trying to spot the damn thing while this balloon is finishing up. It’s ten billion percent insane, I have no idea how we’ll do this.”

“And I’m sure people will recognize that, Senku-chan. No one will fault you for taking some time for yourself.”

Senku makes an indescribably disgusted noise in the back of his throat.

Gen tries to swallow down his irritation. Senku rarely gets into these moods, but when he does, it can be hard to get through to him. He can be as hard-headed as Taiju, as stubborn as Magma. The issue with often being right is it can be difficult to be graceful when you are not. If Gen didn’t love him so much, he thinks he would leave. Would storm out, ignore Senku, sit next to Ukyo at dinner and spend his days helping Ruri instead of engaging in the tedious, physical tasks that further Senku’s visions.

Unfortunately, Gen does love him. Has proved that time and time again, with sweat, with blood, with coy words and slight-of-hand, has risked the hatred and fury of the most dangerous people alive to help Senku get what he wants.

So he tries again. “Senku-chan, I really must insist. Burning the candle at both ends was a good look on Edna St. Vincent Millay, but we can’t all be poetic party-girls, no?”

“I don’t have time for this, mentalist,” Senku says, sounding distracted as he picks up one of his blueprints to squint at.

Gen is sleep-deprived, somewhat hungry himself, exhausted from trying to manage Ryusui from combusting over how long it is taking to get going on the balloon, and something in him cracks a little. “I’m surprised you ever have time for me, given what a waste you think I was in the modern day,” Gen says bitterly, and then immediately wants to slap himself.

Well. No one has accused him of being a saint.

Senku is staring at him, eyebrows furrowed. He looks befuddled as he slowly puts his paper down. His tension is gone immediately, like air being taken out of a vacuum. “What is bringing this on, mentalist?” he asks. He looks so young in the light from his homemade bulb, gray streaks across his cheeks and bags under his eyes. Sometimes, it’s easy to forget he’s only eighteen. Right now, it’s so apparent that it hurts.

Gen feels intensely foolish. His skin is crawling with the embarrassment of losing his cool, shame running down his spine like a spider fleeing a descending shoe. “Ah, never mind! Just all the working and late nights are getting to my eadhay! I’ll leave you to your terrible, terrible labor!” He spins around to hustle out of the lab - he’s not sure where he’ll go, but he can’t be around anyone right now, let alone Senku.

There’s too much. There’s his need to be as important to Senku as Senku is to him. There’s his simmering insecurity about the connection Senku shares with Tsukasa, even though Tsukasa killed him once and almost led to his death at Hyoga’s hands. There’s the fact that Senku almost keeps dying, keeps working himself to the bone, and Gen’s not enough to keep him safe in this new world in which a papercut might be someone’s end.

“Mentalist.” Even when perplexed, Senku manages to have more authority than an eighteen year old boy should be capable of. Gen turns around, even though he truly does not want to.

Senku is standing there, blueprints discarded on the table. He looks authoritative. He looks like someone who should just be starting college. He looks like he can save the world. He looks like someone who shouldn’t have the time of day for someone like Gen. “You know we’re friends, right?” he asks, gently, softly. The fire that burns within him is banked - enough to keep warm by, still with the power to burn down the world.

Gen wonders about that, if Senku would want to be friends with him if he knew the disgustingly painful longing Gen was holding in his heart. He forces himself to giggle. “Ofyay oursecay, Senku-chan!” he trills. Senku doesn’t look assured by this. His brilliant red eyes narrow and he crosses his arms over his chest.

“Then tell me what is actually going on,” he says directly. “I know you ramp up the pig latin when you’re uncomfortable.” Gen finds himself wrinkling his nose involuntarily. He’s of the firm opinion everyone needs and deserves their quirks - he just doesn’t love it when his own become a tell. “Gen. Come on.”

Gen stares at him, wondering what he can even say. “It’s nothing, Senku-chan,” he settles on. “I’ve just been handling some stress since Hyoga almost killed you and Tsukasa. It’s scary to imagine a world with my only source of cola dead.” Maybe a low blow, but Gen isn’t above bringing up something painful to wriggle out of a conversation he doesn’t want to have.

Senku doesn’t react. Infuriating. Gen wishes he was easier to rattle sometimes. “We can’t be keeping secrets from each other like this, Gen,” he says lowly.

“Who said it was a secret? Everyone knows my love for cola.”

“It would be ten billion percent like you to get this weird about something everyone knows if you were like, talking to Ryusui, but not with me,” Senku argues. “You’ve been weird with me for a while now. You keep leaving conversations or looking upset. This isn’t about the fucking cola. What the fuck is going on?”

Gen’s not usually a hot-tempered person. He doesn’t really react by yelling. Subtle sabotage is more his speed. But there’s just something about Senku’s tone that’s grating, like Senku knows best and expects to always be proven right, and he surprises himself by snapping, “Well excuse me for being fucking weird after you almost died - again! For crying out loud, Senku, you are the only fucking reason I am still alive, and you either keep almost dying or working yourself to death. I can’t fucking do anything for you that would actually help! And I can’t help here - every time I try, you just brush me off. I’m going to watch you fall apart and I can’t do anything.”

Senku is staring at him, eyes wide, mouth slightly open. Gen presses his lips together. He’s said too much. Even if Senku doesn’t pick up on the nuances here, there’s just so much - too much for someone like Senku, who has been clear he prefers sentimentality to be discrete.

Senku closes his mouth so sharply his teeth click together.

“I’ll leave you alone for now,” Gen says, feeling oddly desperate to leave. “We don’t have to talk about this, Senku. I’d actually super prefer it if we didn’t.” He turns to flee into the gathering dusk.

“Gen. Wait.”

Senku heaves a sigh. He looks deeply uncomfortable. The charcoal streaking across his face enhances how tired he looks, shading his thin cheeks. He doesn’t quite have the same level of control over his reactions as Gen does, but his poker face is impressive. Seeing him look like he’s feeling something more than his usual determination is a privilege.

“When you found me, I was doing my level best to not recognize the fact that Tsukasa had ten billion percent actually killed me, and it was a total fluke I survived at all,” he says quietly. “I felt like I had only just gotten Taiju back, but I lost him to the guy who murdered me. I barely had time with Yuzuriha at all.” Senku swallows. His adams apple bobs. “Everyone is so reliant on me - what I know, what I can do, what I can teach them. I want to revive the world, but...” He sighs, and looks down at his hands. The cut on his pinky has been slowly closing, the faintest line still showing against his pale skin.

“But you’re worried you’re becoming an idol and losing anything about you that was human,” Gen finishes quietly.

Senku huffs. “Something like that, but worded less cringy,” he grumbles. He takes a step towards Gen, looking slightly like a spooked cat being tempted with fresh fish. Slowly, as if giving Gen time to pull away, he reaches out, and touches Gen’s hand with his own.

Gingerly, as if not wanting to scare him off, Gen turns his palm slightly, and Senku tangles their fingers together, moving as cautiously as he does when pouring acid into something. His skin is cool and dry, his grip reassuring and confident.

“You still see me, even in all this,” Senku whispers to him quietly. “And I kind of need that, right now.”

They stare at each other in silence. Gen slowly squeezes Senku’s hand, feels the delicate shift of his bones and tendons, feels his fluttery pulse underneath his fingertips. Senku breathes in steadily, and doesn’t look away.

It’s just them in the lab. Outside, Gen can hear the low chatter of people winding down after dinner, the far-off noise of insects, the gentle swishing of the waves. He feels suspended, out of time. Unlike with the petrification, it doesn’t feel dangerous. It feels important, feels on the cusp of dawn, like the moments before he burst out of the stone into a new world, like the moment after Senku first met his eyes.

“Senku,” Gen murmurs, “Forgive me if I’m reading this wrong and say no if you don’t want this, but I really would like to kiss you.”

Gen is very slightly taller than Senku. Watching Senku tilt his head back, the ghost of his smirk on his face even though he’s clearly uncertain, is slightly intoxicating. Gen can feel Senku’s breath against his lips. He smells of chemicals and the yuzu tea with honey that Yuzuriha has been making.

There is something beautiful about potential being realized. A rubber band snapping. A diva hitting the highest note. Winning a field’s top prize. A star exploding. All these forms of work and action and energy coming to full fruition. When Gen dips down the slightest bit to press his lips against Senku’s, he feels like this is what his life has been working towards, contained within a moment.

It’s not fireworks. It’s more like the universe is suddenly making sense. Gen feels like he’s worked out every philosophical quandary, resolved every lingering physics mystery. The answers to the meaning of existence and why he’s here are found in the slight pressure change of Senku inhaling, the way Senku’s deceptively strong hand grips Gen’s forearm and pulls him ever so slightly closer. He’s still holding Gen’s hand.

Senku kisses like how he does most things - somewhat sloppily, but with full determination to explore every aspect, to improve, to see it through. He pulls Gen closer, no hesitation at all, and bites down gently on Gen’s lower lip. A galaxy is born in the dark underneath Gen’s eyelids. Gen traces his thumb along the ridge of Senku’s cheekbone, tilts his head to kiss him deeper, trying to pour everything he thinks he might never give voice to into the kiss.

They kiss until Gen is light-headed, until he’s worried about running out of air. He pulls away, panting, still cradling Senku’s jaw in his hand, his other hand still tangled up in Senku’s own. Senku is also breathing hard, pale skin flushed, eyes shut. The fingers on the hand still clamped around Gen’s arm twitch, as if considering pulling him back in. Slowly, he opens his eyes. The crimson of his irises is almost consumed by the black of his pupils as he blinks at Gen.

Gen can’t help the smile that breaks out across his face as they look at each other. He feels so giddy that he could run a marathon, scale Mount Fuji, swim across the sea, fight Magma and win. He’s punch-drunk, somewhat delirious, joy bubbling through him like a violently shaken bottle of champagne.

Senku frowns at him, although his eyes are bright and he’s clearly working hard to repress a grin. “What the fuck, mentalist, you look creepy like that,” he snarks, but his words are shaky and he squeezes Gen’s hand hard right after he finishes talking.

“Oregivefay me, Senku-chan,” Gen says back, too happy to moderate the clear delight in his tone, “I will make sure to get back to regularly scheduled programming of irritating the hell out of you.” He strokes Senku’s cheek gently, and can’t help asking, “How do you feel?”

Senku’s eyes narrow. “What, need compliments on your kissing skills? You’re exceptional, mentalist. Ten billion points to you.”

That does admittedly cause a flutter in Gen’s stomach. Senku’s directness can be charming, sometimes. “I appreciate the kind words, but that’s not what I meant. I didn’t think you would ever want this.”

“I don’t spend a lot of time sitting around thinking about kissing people, no,” Senku says, straightforward as always. “But you’re different. You always have been.”

“Even though I’m a trashy mentalist?” Gen jokes.

“Yeah, somehow. I don’t know. You’ve grown on me, I guess. Like a fungus, a millimeter at a time. Hey, did you know slime molds can solve mazes?”

“Your grasp of the art of romance is truly astonishing.”

“Ugh.” Senku sighs. “Mentalist. Look. I am not good at this. This isn’t something you can make a blueprint for. All I know is that I like you, I like kissing you. I do better when you’re around.”

“I like you too,” Gen says softly. “I told you, on your birthday in the observatory. I’ve always been fond of you.”

Senku wrinkles his nose. “Gross,” he says, and Gen lightly smacks his cheek. “Oi. What was that for?” He doesn’t actually sound irritated, sounds at peace.

Gen shifts forward, presses just a breath of a kiss on Senku’s lips, feels them give under his own, feels him inhale shakily as he pulls back. It feels so wondrous, so strange, to do this so freely. “As much as I would love to keep this moment forever, dear Senku-chan, you do need to actually eat,” Gen says gently. “I know you haven’t today.”

“Keep a moment….” Senku murmurs, looking down at his fingers wrapped around Gen’s arm. He looks thoughtful, much like he does in the dawn hours before the day truly begins and the moon is still glowing, but then suddenly his eyes widen and he lifts his head to meet Gen’s eyes with the unholy light of a project that might be a lot of work brightening his expression. “Mentalist, ten billion points to you. Cameras! I need those on the list! We can use those to help with finding the oil!”

Gen can’t stop himself from laughing. This thoughtful, intimate Senku is wonderful, but Gen has first and foremost always been dedicated to the madman he knows Senku to be, who will make someone pump a furnace to melt steel in exchange for absolutely awful ramen and act like making glasses for a child was solely for his own benefit. He loves this person who is facing tremendous odds, who if he can’t find a way around or over a problem, will force his way through anyway. “We’ll add it to the list,” he says, and tugs Senku forward into a hug.

As Senku wraps his arms around Gen with no hesitation, Gen thinks that he was right - the date carved on the tree did mean something. At the very least, it brought him here - past the end of recorded history, beyond a eon locked in stone. Gen is here, now, with the person he loves more than anything, finally on the same page.