Work Text:
Bringing humanity back from the brink of extinction and rebuilding civilization in a primitive world left one without downtime. Any time that was not spent directly on inventing, building, or scavenging, was spent on things just as part of the curriculum as the aforementioned: eating, sleeping, keeping clean so as to not die of sickness before bringing society back. That took a lot of brain power, Senku found himself constantly thinking. That energy he was burning through made those actions such as eating and sleeping, that would have been mundane and casual tasks in his world, significant steps towards survival in this one. He had no time for true rest, when he woke up every morning he only felt less exhausted, not rested. He had no time for things such as hobbies, no time to experiment on things he would have found interesting if he had the time to indulge. Of course, everything he was doing was exciting to him, but it was different. Everything he was doing belonged to humanity, not to him. He didn’t have anything that belonged to him any longer,not even his own brain. An individual turned vessel for restoration, Senku found himself wishing he could indulge. His brain may be entirely logical, sure, but his being wasn’t. Even he had moments of selfishness like this.
On his birthday, looking at the telescope that the village had made for him while he was down in the caves. He thought for a moment that maybe his identity was not as gone as his humanly and stupid emotions had made him believe. He doesn’t get into any of that mushy stuff, so no one should have expected him to start tearing up and kneel over in awe. Though, in the way his teeth clamped around the corner of the inside of his bottom lip as he slowly grinned, and how he felt his eyebrows lower, this gift did not go unappreciated. Of course the first thing he thought of was the telescope that Byakuya gifted him when he was a kid. The second was when Taiju came over the very next day excitedly looking around for what this “great thing” Senku had to show him was. The third was Senku covering his ears as Taiju’s jaw dropped. “That is outer space!? Are you serious!?” “Yes I’m serious you ox! Now shut up my neighbours will think we’re getting ourselves in some serious trouble!”. Those moments felt so far away. It is in moments like these when it hits him just how long thousands of years are.
“Why are you following me, moon?!” He had asked in frustration. His small fists hitting the concrete of the path he had stumbled and fallen down on. Byakuya laughed in his low and rumbling voice, as if his voice was of sediments shaking in a ceramic jar.
“Maybe the moon has a crush on you!”
Senku’s face had scrunched up in disdain when he heard it then, and it scrunched up in disdain now as he remembered it. What a stupid thing to waste his time on.
“So?! Do you like it?!” Suika chipped from beside his knee. He blinked and the image came back into focus. The night sky. His allies standing around him leaning forward on the balls of their feet, leaning in to see a reaction. The way their clothes swayed with the crisp winter wind. The breath condensing in front of each other. The telescope directly in front of him angled to the speckled sky. The creaking of the wooden floors as he shifted his weight, bringing his hands into his pocket and closing his eyes. He scoffed.
“Of course I do.”
The room let out a collective sigh of relief and excitement. Senku approached the telescope and knelt in front of it, bringing the cold material to his eye. His lip twitched upward as his nose scrunched and he strained his focus. His shoulder rising and lowering, betraying his stoic expression and tone.
“Defintely not the grade of tech I’m used to. But It’ll do.” He said with a nod, then he added. “Yeah, it’ll do.” Quieter this time. Gen, with his hands clasped in front of his chest, looked down at him with a raised eyebrow.
“Is that really all you have to say? I spent a long time on this, you know. Even painstakingly counted out when your birthday was.” He sighed in a sing-song voice, “eriously say, Senku, you ought to show more appreciation.”
“Not my style.” Senku said in a dismissive voice as he returned his vision through the lens of the telescope. Gen rolled his entire head along with his eyes. A few moments of excited chatter happened before Gen looked down at him and saw that he hadn’t moved an inch.
“Well!” He exclaimed with a dramatic yawn. “It is getting late, might be about time to hit the ay hay.” Gen and the others descended down the ladder in a single file line. Gen being the last to leave.
“Senku dear,” He said in a patronizing voice, like warning a child, “Don’t stay up all night playing with your toys.”
Senku’s jaw twitched before he looked over his shoulder with a prideful grin, raising his chin “Get out of my room.” He chided.
During the day, the telescope was used for surveying the land around them. Looking far into the distance to look for any signs of the Tsukasa army. At night, when everyone around him had gone to bed, Senku decided something. He did not often have nights where he could not sleep. With the amount of energy he was spending each day, sleep came like second nature. It was illogical to not recuperate, that was a way to get yourself killed for no good reason, ten billion percent. There are some nights, though. Senku laid next to the dying fire, not quite asleep yet. He’d put it out when he felt his eyes closing on their own. He looked up at the observatory with glossy eyes. Maybe from the exhaustion. For a moment though he was sure he saw himself and Taiju standing in the opening. Senku was pointing something out in the sky and Taijiu had the telescope pointed in the completely wrong direction. They looked younger than Senku remembered them. His jaw tightened and he sucked on the back of his teeth, letting them go with a dense popping sound, and redirected his eyes to the grass. He sat up. His abdomen and shoulder blades are in a state of dull soreness. He rested his weight on a hand behind his hips and stared right into the fire. Chrome, beside him, was knocked out. Snoring softly. Gen was on his other side, curled into a ball on his side and twitching gently in sleep. How long has it been since he was with Taiju and Yuzuriha? Coming up on a year surely. Senku’s hand gripped the fabric below it, knuckles straining. Thinking about things like that, especially late at night, was a sure fire way to get him to feel things he really didn’t want to. Yeah, his brain is the most logical thing…but his being isn’t. Slowly his neck craned to look at the observatory again. This time Taiju and him were gone. Reality was seeping its way back into his vision.
‘Well there goes my rest.’ He thought to himself, feeling exhaustion slowly bleed from his body. ‘Guess I can’t sleep.’
Slowly, he pushed himself onto his knees. The ruffling of the fabric, grass, and leaves much louder in the dead of night. He stomped on the fire before walking away, stepping over Chrome’s sleeping figure. Walking alone at night isn’t something advised, but he wasn’t going too far anyway. A walk would surely help him return to a state where he could succumb to sleep. Walking away from where the boys slept, he placed his hands in his pockets, fabric slightly cold from the brisk air. He looked up, walking while staring at the stars. The clouds were rarely clear for this time of year, he could make out constellations he knew. Before long he ended up at the base of the structure that had become the home base for the Kingdom of Science. He climbed the ladder that led to the interior, and the second one that led to the observatory. He approached the telescope with a sad familiarity. He did appreciate it, although it was a shell of the gift he had been given. Byakuya worked his ass off to get him that tech for Christmas. Even did the fatherly duty of playing it off as Santa. The both of them knew that Senku didn’t believe in crap like that.
Senku ran a hand through his hair, bending over to look through the lens. He gently cradled the star diagonal. His other hand came up to brush the finderscope. He shifted the scope to look side to side, finding a spot from where to appreciate the stars. He looked for the northern star first. Chuckled to himself when he remembered the North had changed from where he knew it. This really was a completely different world, did that mean the stars were different too? Did he need to learn an entirely new map? He found it, the twinkling movement of lungs slightly brighter than those around it. Senku let his lips part.
“Well I know why you were so obsessed with getting there.” He whispered to the empty room. “They’re pretty damn amazing.”
Minutes passed as he gazed into the stars. He could imagine what Taiju and Yuzuriha would say if they were here.
“Senku?! Are you saying that all of those stars are more than every grain of sand!? Are you for real!?”
“So there are thousands of galaxies out there? Makes you think how crazy it is that we ended up here!”
Senku removed his eye from the lens and leaned his elbows on the edge of the opening in the observatory. Taking in the big picture, watching his breath condense then dissipate into the black void above him. He rested his cold cheek against the brisk fabric of his arm, looking down at the camp below him. The copper generator, the many inventions that he, Chrome, and Kaseki were working on, the glass furnace, everything he had after starting with two rocks in his hand. He did feel like a king overseeing his kingdom, a weird and prickling sensation arose in his chest. It really does make you think how crazy it is that we ended up here. Maybe not crazy, it’s science. Science would have always gotten humanity here to this moment of realization of progress. It’s just how human beings are. They and science go hand in hand, you can’t have one without the other.
As his eyes adjusted to the darkness around him. He noticed a figure walking in the distance. Shadow arms came up behind their head, before dropping slowly, like viscous syrup. Their shadow hands clamped above their head as they stretched their shoulders and back, leaning side to side. They walk with comfortability, their arms swinging by their side. They didn’t look up, just down and side to side, their whole upper body rising and lowering with the movements of their head. A sign of reflection. Senku looked down at where the boys were sleeping, and no one had moved. He moved his eyes to the figure once more, it was standing right below him now, looking up into the clearing of the observatory.
“Senku? What are you doing up?” She asked in a low voice. Good thing sound travels further at night.
“Late night stroll, gorilla?” He responded in a low voice as well. She crossed her arms and jutted out her right hip, scowling up at him. He looked down at Kohaku, he couldn’t make out her face very clearly, but he could imagine the one she was making. Scrunched up, pissed off, exactly like the animal he had just compared her too.
“So,” he sighed. “Are you going to stare at me until the sun comes up, or are you gonna come join me?” Company wouldn’t be the worst thing in the world. Sleep clearly was not going to catch up to him.
Kohaku huffed. She began to climb the ladder. “I would’ve assumed modern boys to be more polite."
“Oh they are.” Senku nodded, “Just not me.”
“Well aren’t we lucky.” She chewed on the inside of her cheek as she swung her legs over the top step of the ladder, now standing behind Senku, she approached the clearing, coming next to him.
She looked up. “Ruri has a lot of tales about the stars.” She reached a hand out, like she was trying to grab them.
“You’ll never catch them like that. You need to get closer.” He said, not looking away from the stars.
“Is that really possible?”
“Oh yeah.” Senku cleared his throat. “You could be as close as you could get. Among them. Sometimes we even had people walking on the moon.”
Kohaku’s eyes lit up. “Walking on the moon… people in the stars.”
A few moments of silence passed before Kohaku spoke again. “What are you doing up here so late?”
“Same reason as you, I assume, I couldn’t sleep.”
Kohaku’s knees hit the ground in a soft thump. She turned so her hip pressed against the edge of wall created by the observatory opening. She folded her arms on that ledge and pressed the side of her face into her wrists. She looked up at the night sky with the steady flow of her breathing rippling down her body.
“It is hard to sleep these days. I can’t help but think.”
Senku just hummed, clasping his hands together and rubbing over them half-mindedly, trying to warm them up slightly. He assumed she was expecting him to ask what she was thinking about.
“Anything in particular?”
Kohaku’s eyes suddenly glossed over with an indescribable sadness. Senku’s neck twitched as he looked down at her, his eyes watching hers flutter shut and open with a persistent denial of their closing. His head tilted to the side, the way her body seemed to sink in on itself, as though she were hollow. It caught his attention. It was as if her body had a string going through it, both sides being tugged at immense strength, but there was an infinity to the string that it just kept stretching forever. The exhaustion of that force, though invisible, was painted on her face and through the subtle collapse of her body. She looked nothing like a gorilla, or a lioness, or any other animal he could think to compare her nature to. She looked, in fact, nothing like herself.
“I’m sure someone like you doesn’t want to hear about it.” She said softly. He chewed the inside of his lip.
“Just because I don’t give things I find trivial attention, doesn’t mean I don’t care about them. It is a fact that human beings are impacted negatively when they bottle their emotions inside themselves. The increase in cortisol and norepinephrine can have effects such as memory impairment, a weakened immune and lymphatic system, and increased anxiety.”
“Uhm,” Kohaku responded intelligently, “okay?”
Senku sighed again. “I’m asking if you want to talk about it.”
Kohaku nodded in understanding, then her face scrunched up and she returned briefly to her usual tune. “You’re just as confusing as those processes you and Chrome squeal about.”
“Hey.” Senku said seriously, “I do no squealing.”
That made her face crack into a smile. A pathetic one. A small, and hurried out. Like a breath that came out unexpectedly, and much too harshly. She looked down at the kingdom below them, and laughed again, softer. Then she reverted back to that sad image.
In Senku’s mind was Yuzuriha.
Yuzuriha, when they were in middle school, once had such a problem that she cried almost every day. Randomly, out of the blue. It made Taiju sporadic and panicked, and if he was being honest, made Senku horribly bothered. Not one of them understood why she was crying so often, even Yuzuriha herself. When asked, she just said:
“I just need to.”
The three of them were in the science lab at lunch where Senku was granted permission to stay, so long as no food made a mess, and nothing that had returned to their positions on the wall was moved. Yuzuriha sat with her back against the wall, her knees tucked into her chest, and she let slow tears drop onto her tights. Taiju kneeled in front of her, hands hovering over her shoulder. Asking her to tell her what made her cry, he’d go beat it up in a second flat. That made her laugh the same that Kohaku did just now. A hurried laugh. She shook her head and rubbed her eyes.
“What do you need?” Senku had asked, beside himself. It sounded a little weird coming from his throat.
She looked up at him and her eyes softened. It made his stomach drop slightly. She did look incredibly sad.
“I think I just want you two to sit with me for a while, if that’s alright.”
Taiju sat to her right, looking down at her with the eyes of a hawk, carefully following the movements of her hand to her eyes as she rubbed them again. Senku sighed and sat at her left, with much more distance between them. An arm’s width. Yuzuriha smiled at him before she let her head fall forward to let the tears drip onto her tights once more. She leaned her temple against Taiju’s shoulder, and the three of them sat in complete silence. When the bell rang they finally moved.
“Are you feeling better, Yuzuriha?” Taiju asked in a soft voice. She nodded and he helped her up, handing her bag to her. Senku stood silently. As the two of them wandered to the door of the science lab he spoke to her.
“Better?”
Yuzuriha smiled at him and nodded. “Very much.”
He got it. He understood. It was the company that made her feel better. It made sense to him that company would have made her feel better. What he was confused about was why it worked. Why it worked for some and not others, not him.
He looked down at Kohaku, and sat with his back against the wall beside her. An arm’s width of distance.
“So, do you want to talk about it?” He asked. “Just don’t expect me to say anything back, I’m not good at that kind of thing.” He added.
“Naturally.” She said quietly, her eyes returning to the sky. Then she began to explain. “Ruri’s condition is getting worse by the day. I know we’re creating the sulfur drug, from the stone of life..but I can’t help but being scared that we won’t make it in time. I’ve spent my entire life taking care of her, and now that we have this science that dream feels so real. I kind of hate that it feels so real, because I can’t stand the thought of failing.”
She paused to take a shaking breath. Senku looked directly in front of him. He didn’t want to check to see if she was crying.
“There are many stories in the hundred tales about the stars. In one of them, it’s said that when a person dies and they return to the dirt, their body nourishes the soil from which our plants grow…but their souls go upward. They are each assigned a star to merge with. That way they are preserved forever.” She explained. After a moment she added, very faintly, “It scares me to admit, but at night I look at the stars and wonder which one is for Ruri. So I’ll know which one to look at.”
Silence. Senku decided against speaking out loud what he was thinking. ‘That’s useless practice. We’re going to save her. We are.’
“That probably seems useless to someone like you, though.” She curled in on herself more. “But not to me. I’m not like you Senku, this stuff…it affects me. Badly.”
Kohaku’s sentence was cut off by a tap on her shoulder. Senku was standing now. He tilted his head toward the telescope. “Would you like to get a closer look?”
She pressed her hands into the cold ground and approached the telescope. He held the bottom of the optical tube and brought her hand to the star diagonal.
“Look through this lens here.” He instructed. She bent her neck to look through it. He replaced his hand supporting the tube with hers.
Her lips parted in a gasp.
“Incredible, aren’t they?” He asked, looking up at them himself.
“They are!”
“Science says,” He began. “Stars are loaded with carbon, nitrogen and oxygen. Forged in ancient stars, then those stars essentially exploded and spread those elements across the universe which eventually created planets and life. All the periodic elements were formed in stars, and those elements are the building blocks of the life we know. Meaning, humans are conceptually and philosophically born from stardust.”
Kohaku’s breath hitched. “That’s so beautiful.” She moved the telescope from side to side, looking, searching, exploring.
Senku finally turned his head to look at her. After a few moments he spoke.
“Don’t look for Ruri’s star.” He said sternly. Her face pulled back from the lens and she looked at him with that sad expression. “We’re going to save her.” He said, then he approached her. “Look at this instead.”
He stepped in front of her slightly and peered into the telescope, he chewed on the inside of his cheek as he searched the sky. Finally, he stepped back. “Don’t move anything, just look.”
Kohaku did.
“What am I looking at?”
“That’s the planet Venus.”
“It’s so much brighter than the stars around it.” She observed. “Can you tell me about it?”
“From antiquity to the sixteenth century, it was believed that the planets and sun revolved around the Earth. It was a model known as Geocentrism. People, especially in Europe, thought so because of Christianity. That since humans were God’s creation and God invented everything, He put us in the middle because we were His best work. Then, Nicholas Copernicus discovered it was actually everything revolving around the sun. That’s called Heliocentrism. A key proof of that was the planet Venus. Galileo discovered Venus’ moon, the changing phases of it, and the full view of Venus would have been impossible if it was between the sun and Earth.”
He looked down at her to see if she was lost, but she kept her focus through the lens. So he continued. “Kepler discovered ellipses, which means that orbit doesn’t happen in a circle..more like an oval, and through mathematics he discovered that planets orbit at different speeds. That helped prove Heliocentrism because sometimes the planets and stars looked like they were travelling backward. Really what had happened was Earth passed it. If the Earth moves, it couldn’t be in the center of everything. Of course now with more advanced science actually everything moves all the time around each other- but we don’t need to get into that.”
“What about the spaces between stars, what is there?”
“I guess that’s next for us to discover.” He responded.
She chuckled. “I like the part about discovering humanity and the universe, less in a science and math way but more in a…feeling way.”
Senku smirked. “So you’ll like this next fact. Galileo was called by the Church, and demanded to repent all of his scientific proof. They thought it was heresy, which meant going against the teachings of their God. Being known as a heretic back then was basically a death sentence."
“So what did he do? Did he give up science?”
Senku scoffed, “Of course not. Of course, he did kneel in front of the Church and say he made it all up, and repented. But, under his breath, in that kneeling position he whispered four words that held the weight of all his life’s work.”
Kohaku anxiously asked, “What were they?” She pulled her face away from the lens and looked at him expectantly. He grinned down at her, and recited:
“And yet it moves.”
“Wow, so he didn’t give up on science.” She said excitedly.
“No scientist does. He was simply ahead of his time.”
“It’s incredible.” She sighed. “All of it. I don’t get it most of the time, but it makes me feel- so..-”
“Excited?”
“Yeah.” She smiled. “It does make me feel excited.”
Senku couldn’t really tell if she was feeling better. Though, she did look less imploding-prone. She then looked out of the clearing.
“Sorry I bothered you in your observatory.” She said sheepishly. He shrugged.
“Taiju made telescopes more of a two person activity for me anyway. I don’t mind.”
The air went silent again. “You must miss him.” She said, not as a question, but as an observation.
“Sure.” Was all Senku said.
“It had to have been scary, sending them off to Tsukasa’s army. Alone.” She continued. He closed his hand into a fist and felt his finger nails press into his palm and shrugged.
“They’ll be fine. They always come through. No need to be worried.”
Kohaku stood beside him, leaning against the edge of the wall. “You’re anxious to get everyone back out of stone, I am too. I want to see this world you’ve been telling us so much about.” She sat down on the ledge and looked up at the stars.
“Of course, I want to get it done as quickly as possible.”
“Is there someone waiting for you, someone in the stone?”
“Nope.” He said concisely. “Taiju and Yuzuriha are kind of all I’ve got from my old life.”
Kohaku hummed. “I’m sure that’s not true.”
“How would you know better than me?”
“Maybe you didn’t have anyone else you cared for, but that doesn’t mean no one cared for you. I’m sure there’s some girl waiting for you, even if you don’t know it.”
Senku raised an eyebrow. “You must know I don’t have time for this.”
“Even when the world is back to how it was and you don’t have reviving humanity on your to-do list?”
“Maybe more so then. But I’ll always have my next project.”
Kohaku smiled, down at her knees like she didn’t mean to smile.
“What are you so happy about?”
“Nothing,” She shook her head. “You’re just…you’re a really nice person, Senku. You may not be emotional, but you did make me feel better. In fact, you’re making the whole world better. I think you do care, in your own way.”
Senku pushed two knuckles firmly into her shoulder. “What are you? Some shy pre-teen confessing a crush? I don’t need your praise.”
Kohaku kicked his shin playfully. Senku sucked in a breath through tight teeth to not wince, bringing his hands back into his pocket to squeeze them in secret.
“Yeah it’s hard not to miss the old world. But there’s no use throwing a fit about it. Better to get a move on before we start crying.” He scoffed. Kohaku nodded.
“You probably broke a lot of hearts in the old world. With you not putting a focus on love or all that.”
“What do you mean by that?” He asked, surprised. “Kohaku, don’t go falling in love with me. I definitely don’t have time for that.”
Kohaku kicked his shin more aggressively this time, he did back away and grab at the stinging spot on his leg.
“I didn’t mean that!” She huffed. “Actually, now I won’t pay you the compliment.”
“Now you’re breaking my heart.” Senku said in a deadpan face. Kohaku rolled her eyes with another huff, but it wasn’t aggressive. He noticed she was still smiling. “Let me guess. I’m just so stupidly handsome that by ignoring every girl for science instead I’m just a tantalizing piece of fruit on a tree.”
“You’re such a boy.” Kohaku groaned. Senku rubbed a hand over his face.
“Point is, there’s no bother asking. I don’t care about what stuff right now. Maybe I will later, I’m no future teller, but there’s a one billion percent chance it won’t be in the foreseeable future.”
“Never had a first kiss either then.” Kohaku observed. “You’re right, there are much bigger things to worry about. I agree with you, don’t misunderstand me. I was just curious, that’s all.”
“You haven’t had one? That’s surprising.” Senku noted.
“What am I? A tantalizing piece of fruit on a tree?” She smiled at him. He scrunched his face at her.
A few moments passed before Kohaku’s face eventually showed evidence of sleep. Her eyes fluttered and her hand came up to cover a yawn.
“You should go to bed. I need you energized for tomorrow.”
“You should go to bed. We need your stupidly smart brain tomorrow.” She snapped back, in a clearly tired voice.
He raised his hands, “Now now, no need for such a hostile attitude.”
Kohaku pushed herself up from her seated position and approached Senku.
“Thank you.” She said quietly. He remained silent. “For letting me look through your telescope, for showing me that. And thank you for making me feel a little better.” She explained in a whisper.
He just nodded. He returned to the telescope and began to peer through it. Kohaku kneeled beside him, and pressed the knuckles of her pointer and middle finger to her lips, grazing, gentle, faint. She brushed them against his own, and he jutted back from the lens. He looked at her with slightly parted lips as her fingers drew back.
“You know tha-“
“I know. It wasn’t anything at all.” She said quietly. “Just a ‘please don’t stop showing me cool things once society is back gesture’ She paused. “Maybe that’s what’s in between the stars, this is a goodnight.”
Senku felt his jaw tighten. He couldn’t bother himself with this, but she wasn’t completely transparent to him. He saw her. Right now, in front of her. He felt the warmth seeping off of his lips.
“Goodnight.” He said back, quietly. His jaw relaxed. Then she was gone and he looked back at the night sky. He then brought his eye to the lens once more and focused it on the planet Venus. He brushed the pads of his fingers against his bottom lip and scoffed, lips peeling back into an incredulous smile.
“What a bother.” He said, but there wasn’t any real bite behind his words. His eyes pulled back to look down below him, he saw Kohaku jump down from halfway up the ladder, landing gracefully and leaving to return to rest. He, despite wanting to look away, watched her walk, the shadows engulfing her inch by inch as she got further.
“Yeah,” he repeated, “What a damn bother.”