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Izuku sifts through the cardboard box crammed into a corner behind the couch. A monstera pokes him in the eye, and the hot air coming from a vent on the wall leaves a film of dust on his clothes. Izuku’s nose wrinkles with a threatening sneeze.
“Dammit, Izuku”—Katsuki throws the adjacent bathroom door open—”did ya use my damn shampoo again?” He stands dripping in the doorway, gripping a towel around his hips with a pointed, familiar glare.
Izuku sits back on his knees to look at him better. The sight of Katsuki's half-naked form causes heat to coil in his gut. “I told you, I forgot mine, Kacchan.”
Katsuki’s loud groan fills the room.
Somehow, the only home he knows as well as his own became completely uncharted territory within the span of just a couple of days. Izuku doesn’t blame Katsuki for his added testiness, given the situation, but it stings all the same. He can’t really fault himself for being uncomfortable either; it only aggravates Katsuki more, though. It leaves them in a cruel cycle that’s reminiscent of years when they couldn’t speak without friction.
It can’t be helped that they don’t know how to navigate this—living together, sharing everything, being married. Izuku feels a hollow pang in his chest at the bitter thought.
It shouldn’t be this hard; Izuku knows that. He and Katsuki don’t fight like this, not anymore. They learned years ago that for every single thing that matters, there are a hundred disagreements to be had about things that don’t. And their friendship—the thing that matters most—is the most fragile and precious.
“So? It’s been days, Nerd,” Katsuki huffs. “When the hell are ya gonna get your crap?”
Izuku’s chest aches again, sharper this time. He tries to rub it away with his palm. Katsuki’s stony expression falters at the sight, his fingers instinctively pressing to his own chest.
The truth is, Izuku doesn’t know what to do about his “crap.” This is a temporary arrangement, after all.
“Three weeks,” the old man, whom they had saved less than an hour earlier, rasped. Amidst the commotion of a minor villain attack, his quirk had struck them both.
His granddaughter stuck to his side, still looking slightly spooked. She couldn’t have been any older than a kindergartener. Izuku patted her head and earned a wobbly smile in return.
“Three weeks of what, Old Man?” Katsuki leaned closer, his shoulder bumping into Izuku’s. “Spit it out.”
Citizens stopped to gawk at the heroes as they passed them on the sidewalk. Children pointed and waved while others whispered, “That’s Deku and Dynamight…”
The older man looked between the two heroes, his eyes crinkled, his gaze glinting with sharp gold in the waning sunlight. “You’re stuck being married,” he answered plainly.
Izuku and Katsuki turned to each other with simultaneous, mirrored expressions of horror. Blood rushed to Izuku’s head as he took in the sight of his lifelong friend—and now somehow his “husband.”
“Like hell we are.” Katsuki’s hand sparked as his wide eyes narrowed from shock to defiance.
Katsuki’s face immediately twisted in regret, thinking he had caused Izuku to double over in pain—until he felt the same ache force him to his own knees.
They learned the most important caveat of the quirk the hard way: breaking the conditions of being a married couple causes them physical pain.
With little other choice, Izuku moved into Katsuki’s apartment, just until the quirk wore off. It should’ve been easy enough; he usually spent plenty of time there anyway—sharing takeout meals at the kitchen counter, buried beneath blankets on the couch while watching movies, crashing for the night when it got too late to go home.
Proximity wasn’t enough to satisfy the quirk, though. He spent every night alone on the couch, tossing and turning from the pain in his chest. It turned out that meeting the expectations of the quirk was more difficult than either of them could have imagined.
Izuku shrugs, standing with his clean set of clothes held close against his chest. “Is it really such a big deal? I’ll buy you more, okay?”
Katsuki’s hand falls away from his chest. “Do whatever the fuck ya—” The harsh words cause him to grimace at the throbbing in his chest, and he spins on his heel. “Do whatever ya want,” he chokes out weakly and stomps off to his bedroom.
The ache Izuku feels only gets stronger as he watches Katsuki disappear around the corner.
It might be easier to pretend if his heart were in it. But how could it be, when it was long since tangled in a hidden truth? It’s a secret Izuku will take to his grave in favor of spending the rest of his life as Katsuki’s friend.
Following nonstop petty arguments for the first several days, avoidance becomes an unspoken agreement. They are both too vulnerable to continue the mean, senseless arguing. Even Katsuki starts to look worn after one too many spats.
Afternoons go by with solitary lunches and walks home—or rather, to Katsuki’s apartment—instead of meeting together like usual. Cold, gray evenings pass with partner-less patrols.
Izuku would be lying if he said it wasn’t lonely, but he’d also be lying if he said he wasn’t complacent with the distance.
On the scarce days that they see each other at the apartment, they only exchange curt greetings. Most nights, the lights are off, save for a small lamp in the kitchen; Katsuki is already locked in his room, and extra, lukewarm food sits packaged neatly in the microwave. At least some things don’t change.
Izuku finds himself burning out like a match. Between not sleeping and the daily ache filling the void where his best friend should be, he’s completely exhausted. He wonders why he’s staying at Katsuki’s at all, but the thought alone only makes the twisting in his chest worse.
After over a week of quiet separation, Izuku drags his feet into the dimly lit apartment. It’s already past midnight. The solitary light offers a faint, warm glow, making the space feel more intimate.
Katsuki sits at the counter, chin propped in his hand with disinterest; his eyes are shadowed with exhaustion that Izuku immediately recognizes. The longing to check on him like he usually would is trailed by a dull throb in his chest—or maybe the pain only feels dull because his entire body is on the verge of collapsing. The tension keeps getting worse as the fissure between them grows, and by the look of Katsuki, he isn’t doing any better.
“Ya look like crap,” Katsuki mumbles. The familiarity makes Izuku’s heart yearn for more of their usual conversations. “Come sit and eat.”
“And you look tired,” Izuku whispers as he sits beside him. “Thank you for the food.”
He unwraps the home-cooked meal from the steaming container. The scent travels warm into his chest and settles in his bones, easing some of his pain.
Katsuki dismisses the “thank you” with a short hum. “That’s ‘cause I feel like crap.”
“Me too,” Izuku agrees as he prods the food with his chopsticks.
“This isn’t working, Izuku—actin’ like the quirk doesn’t exist.”
Izuku shrinks into himself and nods. “I know. You’re right.”
“M’sorry,” Katsuki says, his voice muffled by the hand propping up his chin, his eyes directed at the couple of pictures held by magnets on the fridge. Izuku had put those there when he first helped Katsuki move in: an old class photo, family pictures, and a few shots of the two of them.
“It’s my fault it got like this. I was being a jerk about everything. It’s just…” Katsuki's voice falls away.
“Weird?” Izuku looks at the photos too. In one—from when they were on their first patrol together after Izuku got his suit—their cheeks are pressed together. Katsuki looks less happy about it, but Izuku remembers how tightly he held his side that day.
“Yeah, I guess.”
“It’s not only your fault. I don’t know what to do either. I haven’t helped much, really. I’m sorry, too.” As the words fall honestly, Izuku feels more of the pain in his body leave with them.
Katsuki lifts his head to look at him. Lamplight reflects like embers in his eyes. “We can still make it better for the rest of the time. Let’s try,” he offers with a delicate expression that makes Izuku’s breath catch.
Before Izuku can respond, the screech of Katsuki’s stool cuts through the silence. Katsuki wraps his arms around him in a tentative hug, his cheek pressing into green curls. His fingers curl into Izuku’s back almost painfully tightly, despite how the rest of his body moves with hesitation.
They’ve hugged once or twice when their feelings were too big to contain. In a perfect world, Izuku would belong here all the time. Against his better judgment, he lets himself melt into Katsuki's touch. It’s warm and comforting—everything he dreams of. Izuku clenches his jaw to mask the shaky breath he lets out.
Katsuki pulls back, to Izuku’s disappointment, looking pale and uncertain. “I just… thought that might work.”
Izuku blinks a couple of times as he processes. He realizes he feels much better; any pain has been reduced to barely noticeable soreness. “It did.”
“Yeah,” Katsuki agrees, rubbing the back of his neck almost shyly. “I gotta shower now. Ya get home way too fuckin’ late. Make sure ya eat your damn food, got it? We’ll talk tomorrow.”
Izuku nods, still too shocked to argue.
The ache returns when he lies alone on the couch that night. Katsuki's closed bedroom door mocks him—a reminder through the late hours that everything is pretend.
The warm scent of coffee wakes Izuku in the morning. He lifts his head in a daze to peer over the back of the couch. Katsuki stands in the kitchen, lingering over the coffeepot with a stern look, his fingers drumming on the counter. When he catches Izuku’s gaze, he offers an almost-smile that makes his heart backflip.
“Mornin’,” Katsuki mumbles sleepily.
Until today, Katsuki had been long gone before Izuku dragged himself off the couch each morning. His body feels a little less heavy when he makes his way to the bathroom today. He thinks it might be because the apartment, usually dark and empty, has someone worth waking up for.
He sinks onto the stool at the counter when Katsuki waves him over. The taste of toothpaste is still fresh in his mouth.
“Here.” Katsuki sets an All Might mug—the one he keeps specifically for Izuku—in front of him.
“For me?” Izuku asks. The ceramic warms his cold fingers, aching with some mixture of arthritis and quirk-induced pain, as they curl around it.
“Who else?” Katsuki leans onto the counter in front of him.
Izuku drags the cup closer so the steam wafts up and warms his cheeks too. “Thank you,” Izuku whispers.
“I’ve been thinkin’ about—our arrangement.”
Izuku had, rather fortuitously, forgotten for a blissful moment that they’re stuck playing a game of house. He hates the idea of pretending, but he can’t deny how much less his chest aches than it did yesterday.
“I think, if we can just… treat each other how we’d want someone, a lover—” Katsuki grimaces at the label, “—to treat us, then it should at least be enough to make things bearable.”
Izuku’s nails make clinking noises as they tap against his mug compulsively. “Yeah,” Izuku says, but he knows it’s unconvincing the moment it leaves his mouth.
Katsuki drags his fingers down his face with a sigh. “Listen, I know it’s fuckin’ weird, okay? We’re in the same boat, so let’s just—fucking pretend—for now. No judgment or whatever; I just don’t want us to spend the next two weeks in torture.”
At first, the change helps a lot, and not just physically. Icy relief washes over Izuku as some semblance of normalcy returns. He and Katsuki return to their familiar routine: Katsuki walks Izuku to UA in the mornings before their patrol shift, they meet up for lunch and exchange stories and snacks, and they pair up again for evening patrols.
The natural proximity of their friendship almost gets away with being enough to get them through their few weeks of “marriage.” But the closer they get, the stronger the ache drawing them together grows. It becomes difficult to differentiate between the quirk’s appetency and his own longing. Nights remain near-impossible to sleep through, and there’s a persistent dull ache no matter how much time they spend in each other’s company.
Urges spark under Izuku’s skin, compelling him to play out invented scenarios in his mind that he normally would’ve never considered—if only in preservation of their friendship. His imagination wars with the nagging voice of reason in his head, saying it’s selfish—pure indulgence. Taking advantage of Katsuki and the circumstances of the quirk would be a mistake, and that terrifies Izuku.
He opts for inaction instead, staying as stable and inconspicuous as possible.
Katsuki still notices, though; he always does. It’s written in stolen glances and dragging gazes, and in his taut brow and pale fists. But while Izuku rolls over in submission, Katsuki raises the stakes—strikes the way only someone who demands to deserve the best can.
Katsuki leans in when they walk together, until their paths intersect and they’re bumping shoulders and elbows. Their hands graze, doing the most mundane things, from making morning coffee to helping a civilian. They sit side-by-side during their shared lunch break, and Katsuki offers snacks he packed just for him—Izuku knows because Katsuki doesn’t even like them. Katsuki drags him to the tallest skyscraper during their evening patrols to watch the setting sun. Their breaths fog together against the twilight sky as Katsuki rests his cheek on Izuku’s shoulder.
It’s everything—too much for him to even make sense of. Every flutter of his heart eases his tangible pain but comes with an underlying sense of fear. The closer they get, the more dizzyingly the world spins, and the more afraid he is. His guilt surmounts as his heart skips a beat at an innocent, featherlight touch.
They stumble—they’re joined at the arms, intoxicated by the frigid night breeze—into the apartment one night, shivering from the cold. “Izuku,” Katsuki says breathily as he kicks off his boots. His hand stays wrapped firmly around Izuku’s bicep, using it to keep his balance. “Throw the leftovers in the oven. M’gonna shower.”
Izuku nods a silent agreement, pointedly avoiding the sight of Katsuki, who looks sleepy, peaceful, and so, so pretty as they peel apart from each other.
The bathroom door closes heavily behind Katsuki. Only a crack of light seeps out under the door along with the sound of rushing water.
Izuku’s hands tremble when he handles the tray. In the minutes that pass—and he counts each one with his eyes focused on the oven’s digital clock—the world shrinks. It’s a small space where only he and the ghost touch lingering on his skin exist. The sound of water fades into white noise, making it hard to tell if anything really exists.
Katsuki comes back with a frown, his eyes narrowing at Izuku fumbling with his chopsticks. Water drips from his blond hair onto his loose sweatshirt that hangs just below his waistband. The scrutiny makes Izuku squirm. The prepared plate screeches as Izuku slides it towards Katsuki and stands abruptly from his chair.
He wishes his own shower would ground him, but it doesn't have the effect people seem to think it does. He only feels more like he’s in a dream. His thoughts wander aimlessly and freely without any real need to focus on anything imminent; the image of Katsuki persists through every one.
The water starts to run cold before he finally steps out and dries himself off. Steam lingers, blurring the edges of his vision like a dream. He dresses himself in a daze, wishing to mull the cold, bitter ache that lingers in his bones.
In the living room, Katsuki sits curled up on the couch, knees tucked to his chest. He looks warm, soft, and inviting. Izuku wouldn’t mind taking to him like a blanket and pulling him close with all the comfortable effortlessness of one. He doesn’t doubt it would thaw and soothe him.
“Nice shower?” Katsuki asks absent-mindedly as he tugs at a loose thread on his sweatpants.
“Yeah,” Izuku answers simply. He crosses the room and sits on the couch, purposely leaving some space between them. The TV is on, playing some program he’s seen a million times—he’s actually not sure what it’s about—but the volume is too low to hear. “Was the food okay?”
“‘Course. I made it.”
“Yeah,” Izuku answers again before catching his own repetitiveness. “You’re the best cook. I think I’ll miss eating your cooking all the time.”
“Will you?” Katsuki turns, resting his cheek against the back of the couch, to look at him. His thick lashes flutter over his eyes, as if trying to clear his vision. His features are etched with sleepiness, making Izuku want to scoop him into his arms.
“Yeah—yes.”
Katsuki shrugs and says, “I always make too much for myself anyway.” The words hang in the air with a sense of untruth, considering how meticulous Katsuki is about things like that. When Izuku doesn’t say anything, Katsuki speaks again. “Can I ask ya something?”
“Anything,” Izuku says.
“Is it hard for ya to sleep at night? I mean—when you’re alone—does it hurt?”
A lump rises in his throat. For countless sleepless nights, he has fought the urge to knock at Katsuki’s bedroom door. He swallows and forces out a simple “No.”
Katsuki’s face twists in a mixture of frustration and something unreadable. “Liar,” he spits.
“What—” Izuku reaches for Katsuki, but he’s already moving away, muscles tensed to the point of looking painful and eyes burning with anger.
“All ya do is lie and fuckin’ run away,” Katsuki spits, pointing his finger accusingly. Izuku’s lips parting in defense only further irritate him. “Don’t,” he says before Izuku can speak. “Look me in the eyes and tell me that I’m wrong—Tell me that you don’t feel this fucking burning inside you.”
Katsuki grips his chest desperately. The pain in his features becomes evident: the scrunching of his nose, the gritting of his teeth, the tears welling in his eyes. His breath comes in heavy pants, making Izuku scramble forward.
“Don’t touch me, asshole.” He stumbles backward from the couch, swatting Izuku away. “I’m fucking trying, ya’know. And all—all you do is pull away. Ya hate the idea of being with me that much, is that it?”
“No—” Izuku tries desperately. He doesn’t think he could feel worse than he already does until tears slowly start to spill over Katsuki’s cheeks. His heart cracks at the sight; every nerve in his body—every damn heartstring—screaming at him to fix it. There’s no deciphering the quirk’s pain from his own, very true feelings.
“Leave me alone, just fucking die,” Katsuki mumbles without any real threat as he wipes furiously at his face.
Izuku grabs his wrist. It’s met with resistance as Katsuki tries to twist away. They struggle clumsily—pushing and pulling, as they’ve been their entire life—until Katsuki’s back thuds against the wall.
Izuku follows him as he slides down against it, caging him there. “Kacchan, stop.” It’s not a command, but a whispered request. Izuku hushes his cries, his fingers grazing over his shoulders in an attempt to soothe.
Izuku feels the quirk’s ache in his joints and the throbbing in his chest. And, god, he thinks about every gentle touch, every kind act, and every soft word from Katsuki that eased his own pain, and how he never returned any of them in kind. He thinks of how much pain he’d be in now if Katsuki had never offered him those affections.
He thinks of what it would feel like to be unloved—the sting from the quirk swells at just the thought.
The realization that he has been hurting Katsuki that much, this whole time, crumbles any reason or logic he holds above his love for him. Izuku pulls Katsuki’s slender fingers from his pained face. He knows, distantly, that this is a horrible idea, but letting Katsuki think for one more second that he is anything less than the stars in his sky would destroy him.
He presses into Katsuki’s space, which he really has no right to, and molds to fit with Katsuki against the wall. It happens in a blur, and any reason to stop disappears.
His lips meet Katsuki’s with more hesitation than he means to, but that fact is immediately erased by how right it feels. The world stills as the pain in his body, for the first time in weeks, fades away to nothing but a buzz beneath his skin. Izuku’s fingers tremble against Katsuki’s jaw as they catch his tears, but he’s only drawn closer.
Izuku pulls back when he feels Katsuki stiffening beneath him, knowing he owes him at least an apology and explanation before everything between them changes forever.
Katsuki stares at him speechlessly, his cheeks wet and flushed.
“Kacchan, please listen to me,” Izuku pleads. The tingling on his lips makes it hard to talk, but he forces the words just to make sure, if nothing else, that Katsuki knows what he means to him. “I never wanted to make this worse for you. I didn’t realize how much pain you were in—if I had, I would have never just looked the other way. You have to know that—that you mean the world to me.” Izuku searches his face desperately for understanding. “That’s why, I couldn’t stand the idea of you feeling unloved.”
“Fuck you.”
Izuku’s eyes snap to his in shock. “What?”
“Did you just fucking kiss me out of pity?”
“No—shit—no.” Izuku tugs his fingers back through his hair. Katsuki stares at him, lips parted at the uncharacteristic expletive. “I’m trying to tell you that I couldn’t pretend—” he gestures around them vaguely. “The quirk, living together, being together. I can’t pretend because I do love you, and if it’s all some act then I feel like I used you because, god, I want it to be real, Ka—”
Katsuki tugs Izuku closer by the collar, dragging their lips together into a bruising kiss. It’s Izuku’s turn to cry as he melts into the touch.
There’s nothing still about it this time. Their lips move together with fervor, and their hands search each other for the perfect place to hold. Katsuki settles in Izuku’s hair and on his neck, fighting him desperately as Izuku pulls back slowly.
Izuku searches his face, his own hands lingering on Katsuki’s waist. Katsuki’s lips are shiny with spit and bruising where they met with too much force. “Kacchan, I—”
“Say it again,” he whispers and tugs lightly at Izuku’s hair.
“Really?” Izuku asks uncertainly, his fingers flexing around Katsuki's sides to ground himself. “I really want to be married to you, Kacchan.”
Katsuki’s eyes widen in disbelief. The grip he has on Izuku’s hair loosens and, for a moment, Izuku thinks he’s done something wrong. But then Katsuki’s head falls back against the wall with a light thud, and a small scoff turns into a soft laugh. “You’re… fuckin’ crazy.”
Izuku stares, completely lost.
“Not that, for fuck’s sake—” His gaze stays on the ceiling for a moment before he chances a peek at Izuku again. “The other thing…”
“Oh,” Izuku gasps. He sits upright and squeezes Katsuki’s waist firmly enough to earn a small gasp. “I love you, Kacchan.” The words come easily, honest and true. “Does it hurt less now?”
Katsuki’s lips wobble, making Izuku’s heart swell. He nods slowly and tugs him closer. “I don’t feel the quirk at all…”
“Me neither,” Izuku says. Slowly, he pulls back from Katsuki and tugs him to his feet. His fingers twitch nervously. “Maybe it ended?”
“Maybe you broke it with your insane confession.”
“Maybe,” Izuku agrees quietly, letting his hands fall to his sides altogether. Knowing that Katsuki isn’t in pain anymore eases some of his heartache, but a sense of loss accompanies it. “ I guess I should—”
“Izuku.”
“Yeah?” He avoids meeting Katsuki’s gaze.
“I love you too.”
Izuku’s head snaps up at the words. Katsuki’s gentle gaze meets his with affection. “But—”
“Shut up.” Katsuki presses their lips together in a soft kiss to silence him. When he parts, he only does so enough to speak. They’re so close that their lips still graze together. “I want this to be real too, okay?” he whispers. “So don’t go.”
“I can stay?”
“You have to,” he says with a little more characteristic gruff confidence.
“Do I have to sleep on the couch?” Izuku glances at the seat nearby, but Katsuki turns his head back, his gentle fingers at his cheek.
“No. Definitely not.”
“And you wanna be married too?”
Katsuki scoffs, knocking his forehead against Izuku’s. “I’ve been trying to tell you that I want to spend the rest of our lives together, idiot.”
The little girl tugged at her grandpa’s sleeve as they walked home after the close encounter with the villain. “But Grandpa, your quirk—”
He hummed amusedly. “Nothin’ gets past you, ay? That’s right, Grandpa’s quirk lasts as long as two people go on not admittin’ that they’re in love.”
“But why didja lie to the heroes?”
“People like to come to conclusions on their own, y’know. Besides, it almost works the same way, and they have to work through their feelings on their own.”
She looked up at her grandpa, slightly unconvinced.
He sighed with a small smile. “Okay, and maybe it’s a little more fun this way too, hm? They’ll figure it out eventually.”