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The common room in the third-year dorms is always loud on a Friday night, but Katsuki hates it even more when outsiders are around.
They’re hosting a small get-together with a few students from other schools—just people dropping by to talk about joint training drills and catch up and make friends. Most of them know better than to get close to Bakugo Katsuki, whose face looks like he’s ready to commit a felony just because someone is breathing too loud near his coffee.
Shoto, on the other hand, is standing near the snack table looking like a statue that wandered off a pedestal. His hair is a little messy from afternoon training, and he’s wearing a loose blue t-shirt that shows off the faint burn scars on his arm. He looks completely unbothered, which apparently acts like a magnet for people lacking survival instincts.
Enter a second-year from the support course—some girl with bright purple streaks in her hair who thinks being bold makes her invincible. She’s been hovering near Shoto for five minutes, giggling behind her hand, batting her eyelashes, and leaning in way too close to show him some design sketch on her tablet.
"Say, Todoroki-kun, since you're heading up the security gear logistics for the upcoming drill, I figured we could review the blueprints together? Maybe off-campus? Over coffee?" She twirls a strand of hair around her finger, flashing a bright, hopeful smile.
Across the room, sitting on the arm of the couch with his feet propped on the cushions, Katsuki stops chewing his spicy rice cracker.
His eyes lock onto the girl. The absolute stillness in his posture is the first warning sign. Izuku, sitting on the other end of the couch, catches sight of Katsuki’s face, sighs quietly, and just takes a sip of his energy drink. He’s been in class with these two for three years; he knows how this plays out, so he simply turns his attention back to his notebook without making a fuss.
Katsuki doesn’t yell. Yelling means you’re mad. Right now, he’s just territorial.
He stands up so fast the cheap plastic cup on the coffee table rattles. He stomps across the room with heavy, deliberate steps, his hands shoved deep into his pockets so he doesn't accidentally set off an explosion indoors.
The girl doesn't notice him until a solid weight slams against Shoto's side.
Katsuki doesn't just stand next to Shoto; he practically invades his space, leaning in aggressively, pressing his whole body against Shoto's side to stake his claim.
Shoto blinks, looking down at Katsuki with a mild, unreadable expression. His hand instictively and naturally reaches out, his large palm settling firmly right against Katsuki's waist, pulling him flush against his frame without even trying.
"Katsuki? Everything alright?" Shoto questions, his voice a low rumble above Katsuki's head.
"Shut up," Katsuki mutters out of the corner of his mouth, his crimson eyes locked dead on the girl with a look that could curdle milk.
The girl takes a nervous step back, her smile wobbling. "Ah—Bakugo-senpai! I was just—"
"You were just leaving," Katsuki finishes for her, his voice sharp enough to cut glass. He tilts his chin up, glaring down at her until her eyes widen in terrified realization.
She mumbles something about a project deadline and practically trips over her own shoes, scurrying out the door.
Katsuki stays right where he is, practically vibrating with annoyance, expecting Shoto to have at least noticed the glaringly obvious territorial display. Instead, Shoto blinks down at him, entirely unbothered and completely missing the point.
Before Katsuki can even tell Shoto about it, another voice pipes up from behind them. It’s a second-year from the hero course this time—someone holding a clipboard who apparently missed the entire memo.
"Todoroki-senpai? Hey," she says, stepping right into their bubble with a bright grin. "Are you free to look over the training grid schedule for tomorrow? I tried asking the class representative, but he said you handled the perimeter setup."
Katsuki's eye twitches. A literal vein pops on his forehead.
Shoto turns his head slightly to address the new arrival, his hand still resting on Katsuki’s waist. "Yes, I can look at it. Give me a moment."
"Take your time," the girl chirps, leaning in closer to point something out on her clipboard, her shoulder practically brushing Shoto's arm.
Katsuki’s patience snaps like a dry twig.
Before the third girl fully approached them, Katsuki’s hand shot out and grabbed a brutal fistful of the collar of Shoto’s shirt. With a sudden yank, he pulls Shoto straight down, crashing their lips together in front of the entire common room.
It’s demanding and leaves zero room for misinterpretation. Shoto lets out a surprised breath against his mouth, but his hand on Katsuki's waist instantly tightens, his long fingers curling into the fabric at the small of Katsuki's back as he tilts his head to return the kiss.
When Katsuki finally shoves him back a fraction of an inch, his chest is heaving, and his face is burning hot.
The two girls standing nearby stare at them, their mouths open in utter shock as the pieces finally click together. Katsuki glares at them with such pure menace that they both squeak, mutter hasty apologies, and hurry away before he decides to use his quirk.
"Was that really necessary?" Shoto asks, his voice laced with genuine confusion. He blinks slowly down at Katsuki, his head tilting to the side just a fraction. To Shoto, people asking for drill schedules is just background noise, and he completely missed how close the second-year was standing.
"Shut the hell up," Katsuki snaps. He lets go of the shirt hem, crossing his arms tightly over himself and pulling a hard, unmistakable pout. His shoulders hunch up in sulking frustration because Shoto is too dense to realize what was happening.
Shoto looks down at him, tracing the stubborn line of Katsuki's jaw and the bright flush creeping up the back of his neck. The absolute irritation radiating off Katsuki—combined with the fact that he's currently pouting like a kicked puppy—slowly makes the gears turn in Shoto's head. A sudden realization dawns on him.
He finds it entirely endearing that Katsuki gets this fiercely possessive over something so trivial, even if he'd rather swallow glass than admit he was jealous.
Shoto reaches down, his hand wrapping securely around Katsuki’s wrist. He doesn't give Katsuki a choice; he just starts walking, pulling a grumbling half-resisting Katsuki away from the snack table and straight toward the hallway leading to the upper dorm levels.
"Hey! Where the hell are you dragging me?" Katsuki hisses under his breath, stumbling a step to keep up with Shoto’s long strides, though he doesn't actually pull his hand away.
"My room," Shoto replies quietly, not looking back as he pushes open the heavy door to the stairwell, leaving the noisy common room far behind them. "You're clearly upset. We need to talk about your communication skills."
"My communication skills are fine, you bastard—"
The door clicks shut behind them, cutting off the rest of Katsuki's complaints as Shoto leads him down the dim hallway toward the far end of the third-year corridor, already planning how to spend the next hour reminding Katsuki exactly who he belongs to.
—
Three weeks later, the transition from late autumn to a freezing mountain patrol proves that Katsuki’s stubbornness hasn’t evolved an inch.
The wind howling through the high-altitude mountain pass is brutal, biting straight through their hero uniforms and freezing sweat against skin. Class 3-A’s top four are out on a perimeter sweep following a villain sighting.
Up ahead, Izuku and Kirishima are trudging through the snow. Izuku's breath puffs white in the freezing air as he checks the digital map on his wrist gauntlet. Behind them, trailing a few steps back, Katsuki has his hands jammed aggressively deep into his pockets, his shoulders hunched up near his ears. His jaw is locked so tight a muscle ticks visibly in his cheek, and his teeth are starting to chatter slightly against his will. He refuses to admit that the sub-zero wind is cutting right through his lighter-weight suit pants and sleeveless vest, his absolute stubbornness keeping his mouth shut. Admitting he is cold means admitting weakness, which Katsuki would never do.
Kirishima glances back over his shoulder, squinting through the blowing snow. He catches sight of Katsuki’s slightly stiff posture and the way the blond is trying desperately not to shiver. Frowning, Kirishima slows his pace to drop back next to Izuku. Izuku looks back, following Kirishima's eyes, taking in Katsuki’s glaring expression and the tight line of his mouth. A sympathetic grimace crosses Izuku's face.
Not like they can help, Kirishima's suit doesn't have a jacket, and Izuku's suit is practically a one-piece, the top stitched to his pants.
Right on cue, Shoto—who has been walking silently on Katsuki’s other side the entire time—slows his steps. Shoto didn't need Kirishima and Izuku to point it out; he has been watching the shivers through Katsuki’s frame for the last ten minutes. He knows better than to poke a bear whose temper is already razor-thin from discomfort, so he doesn't say a single word of teasing.
Without breaking stride, Shoto unzips his suit jacket. It’s lined with thermal fabric designed for extreme cold-weather rescues. He shrugs it off his broad shoulders, leaving him in just his dark undershirt, and immediately drapes it directly over Katsuki’s shaking frame.
Katsuki stiffens instinctively, his eyes flashing wide as he opens his mouth to snap a warning. But the moment the body-warmed fabric—smelling faintly of cedar soap and Shoto—settles over his shoulders, the biting wind is blocked out. The sheer relief of it chokes the insult right back down his throat.
Shoto steps in close, crowding into Katsuki’s personal space to act as a physical windbreak. He slides a bare hand up Katsuki’s forearm, subtly activating his right side. A steady wave of heat radiates from Shoto’s palm, soaking straight through Katsuki’s sleeve against his freezing skin.
Up ahead, Izuku and Kirishima glance back, take in the sight of Katsuki completely swallowed up by Shoto’s jacket while Shoto warms his arm, and collectively turn back around with a smrik.
Katsuki lets out a long, ragged breath, his teeth finally stopping their annoying chatter. He mutters a string of muffled half-hearted curses straight into the high collar of Shoto’s jacket, but his rigid shoulders slowly drop. Without admitting a damn thing, he inevitably leans his full weight sideways, pressing heavily against Shoto's side to soak up every single ounce of heat as they continue their march through the snow.
"Think they're ever going to stop pretending they aren't completely obsessed with each other?" Kirishima murmurs, shooting a quick, amused glance backward.
Izuku offers a knowing smile, adjusting the straps of his green utility belt. "Probably not."
Behind them, Katsuki is doing his absolute best to pretend he isn't entirely dependent on Shoto right now. The jacket swallows him up; the sleeves hang a good three inches past his knuckles, forcing him to curl his fingers into the warm fabric just to keep them from freezing. It smells overwhelmingly like Shoto—clean snow from his quirk and that weirdly comforting soap he uses. It pisses Katsuki off how fast it stops his teeth from chattering, and it pisses him off even more that he doesn't want to take the damn thing off.
He shoves his hands deeper into the jacket's pockets, glaring straight ahead at the snowy trail. Every time a particularly harsh gust of wind sweeps down the pass, Shoto shifts his weight slightly, angling his body to block the brunt of it while his right hand stays locked firmly against Katsuki’s forearm.
"Stop staring," Katsuki snaps suddenly, his voice raspy from the cold air.
Shoto doesn't look down, keeping his mismatched eyes fixed on the path ahead. "I wasn't staring."
"You were looking at me. I can feel your stupid eyes burning a hole in the side of my head."
"I was looking at the trail, Katsuki," Shoto replies evenly, a quiet note of amusement threading through his voice. "Though you do look rather small in my jacket. It fits you like a blanket."
Katsuki’s head whips around, his eyes flashing hot enough to melt the snow on his lashes. "Say that again and I will blast you off this goddamn mountain, I swear to—"
"Movement," Izuku whispers, stopping the group in their tracks. His voice drops to a low caution as he points toward a cluster of rusted storage containers near the back wall. "Three figures. They match the description from the dispatch."
Katsuki steps up beside Shoto, shaking off the last of his momentary embarrassment and dropping instantly into an aggressive stance. He lifts his hands to snap a quick, intimidating double explosion to light his way and intimidate whoever is hiding in the shadows.
Except nothing happens.
Instead of the usual deafening crack and blinding flash of orange light, there is only a pathetic fizz sound. A tiny spark sputters out against his palm, dying instantly in the freezing mountain air before it can even catch.
Katsuki’s brow furrows hard. He tries again, snapping his palms together harder, forcing every ounce of focus and adrenaline he has. Pop. Fizz. Nothing. Not a single spark.
Panic spikes straight through his chest, though he forces his face to remain a mask of furious denial. The sub-zero temperature has locked his body down completely. His quirk relies on his nitroglycerin sweat to detonate, and in this brutal high-altitude freeze, his pores are sealed tight. He isn't just cold; right now, without his quirk, he's effectively stripped of half his arsenal in the middle of an attack.
Before Katsuki can curse or try a third time, the shadows between the storage containers shift violently. A trio of villains—heavy-set men wearing thick insulated gear and wielding high-powered kinetic rifles—burst out into the open, shouting curses as they spot the heroes.
"Hero scum! Get 'em!"
The first villain sweeps his rifle upward and fires a blast straight toward Katsuki, aiming directly for the center of his chest while he's distracted by his failing hands. It's moving too fast to dodge.
Katsuki grits his teeth, raising his bare hands out of pure, instinctual habit.
Before the blast wave can hit him, a wall of thick ice erupts violently right in front of them, blocking the shockwave with a deafening CRACK. The impact shatters the outer layer of ice, but the barrier holds firm, shielding Katsuki completely.
Shoto is already moving before the ice crystals even settle. He steps directly into the line of fire, placing his broad frame squarely between Katsuki and the villains. He uses his left side to unleash a controlled pillar of fire that forces the attackers to stumble backward, shielding their eyes from the blinding heat.
"Stay behind me," Shoto orders, his voice uncharacteristically sharp.
"I don't need you to babysit me, you half-and-half bastard!" Katsuki snarls back, his voice tight with frustration as he glares down at his useless, dry palms. But despite the harsh words, he doesn't push past Shoto. Instead, he catches the heavy fabric of Shoto’s jacket in his fist, tightly anchoring himself right behind Shoto’s shoulder as the rest of the villains charge forward.
Up ahead, Kirishima hardens his skin, slamming his fists together and driving his shoulder straight into the first villain's chest, sending the guy crashing hard into a rusted metal crate.
Beside him, Izuku moves with fluid speed, cornering the third attacker. With a precise sweep of his legs, Izuku knocks the villain’s feet out from under him and pins him to the frozen ground, securing the bindings with his hero utility cuffs in seconds.
But out of the shadows of the highest storage container, a fourth person emerges—someone younger, an inexperienced kid who had been hiding all along, serving as the backup for the crew. Unlike the others wielding heavy kinetic rifles, this guy leaps out with a frantic desperate glint in his eye, lunging straight at Katsuki with a combat knife gripped in his trembling hand.
Katsuki reacts instantly, pivoting on his heel to throw a punch, but the cold has his muscles locked up tight, robbing his swing of its usual explosive speed. His fist connects awkwardly against the kid's shoulder, throwing the younger villain off balance, but it isn't enough to stop the momentum. The kid scrambles forward, recovering too fast, and raises the knife to stab downward.
"Katsuki!" Shoto yells when he spots the movement, his voice cracking with raw panic as he breaks into a desperate sprint.
Before Shoto can take two steps, one of the restrained villains manages to fire a sudden blast directly into Shoto's path. Shoto is forced to throw himself sideways to dodge the blast, rolling hard through the snow. That fraction of a second lost means he won't reach Katsuki in time. The knife is already flashing down toward Katsuki's chest.
Locked up by the cold, Katsuki twists his torso violently, trying to catch the kid's knife-wielding wrist with his bare hands to force it away, his teeth bared in a snarl of pure defiance.
Right before the blade reaches, a flash of green lightning tears through.
Tendrils of Blackwhip shoot out from Izuku's wrist, wrapping around Katsuki’s waist and shoulders. With a sharp tug, Izuku yanks Katsuki backward through the air, propping him away from the blade and dumping him safely into a snowbank a few meters out of the kid's reach.
The knife plunges harmlessly into empty snow where Katsuki had been standing a second before. The young villain stumbles forward, blinking in shock at the empty air.
Before the kid can even look up, Izuku is already there. With a swift motion, Izuku closes the distance and sweeps the kid’s legs out from under him, slamming him into the ground, pinning his arms behind his back with a knee between his shoulder blades.
"Got him!" Izuku calls out, snapping a pair of standard-issue binding cuffs around the kid's wrists.
Shoto is already at Katsuki's side, his mismatched eyes scanning frantically over Katsuki's gear and arms, checking for any sign of blood or tearing fabric. "Are you hurt?"
"I'm fine, you damn idiot," Katsuki snaps, shoving Shoto's hands away from his chest. He's breathing hard, not from fear, but from the furious frustration of being sidelined by his own useless sweat glands. He glares down at his palms, teeth gritted so hard his jaw aches.
Izuku jogs over, landing lightly in the snow beside them with a concerned frown. "Your shoulder okay, Kacchan?"
"I said I'm fine," Katsuki bites out, aggressively brushing the snow off the front of Shoto's jacket. He refuses to look either of them in the eye for a second, hating the fact that he needed to be pulled out of the fire.
Shoto watches him closely, the panic finally draining out of his face to be replaced by a grounding calm. Without asking for permission, Shoto steps in close again, wrapping his arms securely around Katsuki's waist from behind, pulling him back against his chest and burying his face into the nape of Katsuki's neck to share his body heat.
"Stop being stubborn and let me warm you up," Shoto murmurs quietly against his skin, ignoring the low string of curses from Katsuki.
—
Two days after the mountain patrol, the exhaustion of the week finally catches up to them in the quiet safety of their dorm room.
They are already lying down in Shoto’s bed, the sheets tangled around their legs in the dark. Katsuki is flat on his back, staring up at the ceiling with his arms crossed over his chest, half-dozing while the steady warmth of Shoto’s body radiates against his side, whose arm is slung over Katsuki's stomach. The gym session had drained the last ounce of energy out of them hours ago.
Shoto is propped up on one elbow beside him, watching the faint play of shadows across Katsuki’s face. He reaches out, his long fingers casually tracing a lazy line down Katsuki’s bare collarbone, completely relaxed.
"You were hesitating on your left side during the final set today," Shoto murmurs, his voice soft. "Your form slipped right at the end."
Katsuki cracks one eye open, shooting a glare at the side of Shoto’s head. He doesn't move an inch, but his jaw clenches. "My form was fine, Icyhot. Stop analyzing every damn punch I throw when we're off the clock."
"It's not just your combat form," Shoto continues, completely unfazed by the threat, his tone deadpan. "Your technique has been inconsistent lately. I'd give your overall execution tonight about a six out of ten. Too many teeth."
Katsuki’s eye twitches. He turns his head sharply, staring at Shoto like he's lost his mind. "What the hell are you even talking about? I landed every single combo on those dummies."
"I wasn't talking about the dummies," Shoto replies smoothly. "I meant the kiss you gave me against the locker room door before we came up here."
A violent, hot flush races up his neck, burning his skin bright red in the dark as his mouth drops open in pure shock.
"You did not just rate how I kiss," Katsuki hisses as he sits bolt upright, looming over Shoto. "Who the hell made you the goddamn authority on kissing? You think you're some kind of expert?"
"I'm just being honest," Shoto says calmly, leaning back against the pillows with an infuriatingly relaxed posture, resting his hands behind his head. "You get impatient. You rush."
Katsuki’s pride shatters into a million angry pieces. Refusing to take criticism on literally anything—let alone his kissing skills—Katsuki moves before his brain can even catch up to his rage.
In a flash of motion, he swings his leg over Shoto’s hips and straddles his lap with heavy force. He pins Shoto flat against the mattress, dropping his weight down so Shoto has nowhere to go. With both hands, Katsuki grabs a rough handful of Shoto’s bi-colored hair, yanking his head back to force him to look right at him.
"Say that again," Katsuki dares him, his chest heaving, his face inches from Shoto's. "Say it again while I shut your smart mouth for you."
Shoto doesn't look panicked or intimidated in the slightest. In fact, that tiny, dangerous smirk touches the corner of his lips. He looks up at Katsuki with absolute confidence, letting Katsuki take the reins just to see how far he'll go.
"I think I kiss better than you," Shoto whispers, his voice low and steady.
Katsuki crashes his mouth down onto Shoto’s in a harsh, demanding, completely aggressive kiss, pouring every ounce of his stubborn competitive streak into it. He wants to wipe that smug look right off Shoto's face, moving fast and hard, desperate to prove that he is the one in control.
For a few seconds, it works. Shoto lets out a soft breath against his lips, absorbing the frantic energy. But Shoto’s strength and unshakeable calm have always been his superpower.
Without breaking the rhythm, Shoto’s hands slide smoothly up Katsuki’s thighs, his fingers pressing firmly into Katsuki's narrow waist to anchor him. With effortless leverage, Shoto shifts his hips, using his core strength to roll them over in one fluid motion.
The world flips instantly. Katsuki gasps as his back hits the mattress beneath Shoto's solid weight, his hands instantly dislodged from Shoto's hair as Shoto pins both of Katsuki's wrists easily to the sheets beside his head.
Shoto leans down, his gaze dark, heavy, and completely victorious as he looks straight into Katsuki's wide, furious crimson eyes.
Katsuki thrashes his legs instinctively, his face burning hotter, but Shoto’s weight keeps him locked securely in place. "Get off me, you piece of shit—"
Instead of letting him finish, Shoto shifts his weight, sliding his knees upward until they wedge firmly right between Katsuki’s thighs. He presses in, parting Katsuki's legs wide and pinning him completely open beneath his hips, and connecting their lips again.
The sudden shift steals the breath straight out of Katsuki’s lungs. A sharp gasp breaks past his lips, his spine arching off the mattress as a hot wave of friction shoots straight up his core. Before he can bite it back, a low, humiliated moan slips out, right against Shoto’s mouth.
Katsuki’s hands, previously clenched into furious fists against the sheets, instantly lose their grip. With a shaky, frustrated breath, his fingers slide up, clutching desperately at the broad shoulders hovering over him, dragging Shoto down harder as his hips twitch upward in a helpless, instinctive demand for more friction.
Shoto breaks the kiss for just a fraction of a second, letting Katsuki gasp for air while a bright, sweat-drenched flush paints his cheekbones.
"Not a six anymore," Shoto breathes out against the shell of Katsuki’s ear, his voice rough and deep with sudden heat. "Maybe an eight. But you still have to earn the rest."
"Screw you," Katsuki gasps, his voice trembling slightly as he tries to lock his knees around Shoto’s waist, only to be effortlessly blocked by Shoto's steady weight. "I'll wipe that smug look off your face right now—show me, then. Do it better if you're so goddamn good at it."
Shoto lets out a low, quiet hum of approval, his hands sliding down from Katsuki's wrists to grip his hips instead.
He takes in every single detail of Katsuki beneath him. The stubborn line of his jaw is entirely melted away, replaced by a flushed, sweat-drenched skin that glows in the dim light of the bedroom. Katsuki’s eyes are half-lidded, glazed with heat and hazy frustration. His chest heaves beneath Shoto’s hands, each ragged pant pulling a soft, wrecked sound from his throat, and his lips—bruised and swollen a bruised pink from the friction—stay parted as he tries to catch his breath.
It is a devastatingly pretty sight, and it hits Shoto right in the chest with a sudden overwhelming rush of affection. The idea that this ferocious, untouchable man falls apart this completely under his hands makes Shoto's pulse hammer hard against his ribs.
"What the hell are you staring at?" Katsuki snaps weakly, his voice breathless and ragged. He glares up through thick lashes, his fingers digging frantically into the fabric of Shoto’s shirt, pulling him back down. "Shut up and kiss me again if you're going to do it, you bastard."
Shoto lets out a low, rough sound in the back of his throat. "Alright, pretty."
He swoops down, capturing Katsuki’s swollen lips with a deliberate hunger that leaves no room for argument. This time, there’s no teasing left in it—Shoto kisses him with a deep, possessive thoroughness, swallowing every breathless moan Katsuki tries to bite back. His tongue traces the seam of Katsuki’s lips before sliding deep.
Shoto’s knees press harder against Katsuki’s thighs, parting him wider, while one hand slides up from his waist to cup the side of Katsuki’s neck, thumb brushing gently over his racing pulse. The overwhelming heat of it makes Katsuki's toes curl against the sheets. His back arches off the mattress again in a silent, desperate plea for friction, his hips stuttering upward in a blind search for relief.
Shoto rewards the movement with a slow, heavy grind of his hips against Katsuki's center, drawing a shattered cry straight from the blonde's mouth, swallowed up instantly by another deep bruising kiss. Katsuki’s hands slide from Shoto’s shoulders up into his bi-colored hair, clutching tight handfuls of the strands and yanking downward, desperate to keep Shoto close.
By the time Shoto finally pulls back a fraction of an inch to let them both drag air into their lungs, Katsuki is completely undone—shivering, pliant, and entirely at his mercy, his flushed face pressed hot against Shoto's collarbone as he tries to catch his breath.
"Better?" Shoto murmurs quietly against his damp ash-blond hair.
Katsuki buries his face deeper into Shoto's shoulder, a breathless, defeated huff escaping his lips. "Shut up...ten. You're a damn ten. Just shut up and do it again."