Archive of Our Own ^beta

“Oh, I almost forgot something!” Izuku doubled back into the living room, grabbing his wallet off the coffee table. From the corner of his eye, he caught a wisp of dark fabric rippling through the dark. But when he glanced up towards the balcony, the glimmering night sky was the only thing there to greet him.

“We’re going to be late, Midoriya!” Tenya shouted from the doorway. Shaking his head, Izuku made his way out of his apartment; clearly, his mind was playing tricks on him. He’d need to get that sorted out eventually; he couldn’t have any distractions, especially now with the new hero sidekicks starting at his agency later this week.

Once the familiar click of the front door locking rang out, the glass door of the balcony slid open. Carmine eyes scanned the dimly lit space before stepping inside, a delicate hand running through blonde tresses.

“Too smart for his own damn good,” Katsuki muttered under his breath, carefully slipping off his boots before walking into the apartment. This was the second time Izuku had noticed something about his presence, and he was cutting it close. The blonde shook off his nerves and headed for his destination — the pro hero’s bedroom.

He needed to get his things in order before orientation this week.

“And finally, we find ourselves at the heart of the agency; the communications room! This is where you will report to every morning with your assigned pro to receive updates and assignments. Any questions?”

Vermillion eyes watched an eager sidekick raise her hand high. “When do we get to meet the heroes?”

A few sly snickers echoed around them as the young woman blushed. Their tour guide smiled knowingly, jerking their head towards the back of the room. “Perfect timing. They’ve just arrived. I will be handing out your assignments before you leave!”

Their heads snapped around simultaneously, watching as the pro heroes walked in, dusting themselves off and handing some of their gear off to their interns and sidekicks flanking their sides. A familiar mop of verdant green waves appeared towards the back of the group, and Katsuki’s heart rate spiked.

He’s actually here.

While the blonde had done everything in his power to get this far in his hero career, he hadn’t actually expected to see Deku in the flesh so soon. His palms grew slick with sweat, his gear suddenly an unbearable weight on every part of his body as his face flooded with heat. He wanted to tear his gaze away, but couldn’t seem to muster the willpower to do it. And then, as if on cue, those jade eyes he’d studied for hours on end through interviews and television broadcasts fell upon Katsuki, and the world around them disappeared.

Red. All Izuku could see was brilliant, glimmering ruby; so stunning, it was practically blinding. A shiver rippled through him, heat rolling over every inch of his skin as he feebly blinked away his initial shock. The hero cleared his throat and waved as his gaze flicked over the faces of the new class of sidekicks, trying to greet them all with a wide, toothy smile. Yet within seconds, like a moth to a flame, he was drawn back to those carmine pools that had caught his eye. 

This time around, he took a step back and studied the person they belonged to. Blonde spikes, pink lips pulled into a cheeky smirk; a lean, sculpted form with defined muscles that showed just how much work the young hero had put in to hone his Quirk and moves. When he looked up, those saffron eyes greeted him, scrunched around the edges; the look on his face was unreadable, his lips now forming a scowl as the green-haired man chewed on his lower lip.

Izuku then realized he was staring, rather predatorily. Blinking slowly, he averted his gaze sheepishly, scratching the nape of his neck as he began to follow the rest of his colleagues to the conference room, where they would receive the name of their new sidekick.

Then he heard a gruff, loud “Oi!”, and turned to find the young blonde glaring at him, his hand outstretched. “Bakugou Katsuki, sir.”

Izuku shook his hand firmly, amazed by the softness of his bare skin; he’d assumed the young man’s hands would be covered in calluses from his training, and now he stared at their joined hands, embarrassed at the roughness of his own flesh. Pulling away, he nodded, smiling at the blonde. “Good to meet you, Bakugou. I—”

“Deku! Let’s not piss off the old man; get in here.” Hawks waited for him in the conference room, a playful smirk on dancing across his lips. A warm flush flooded Izuku’s face as he stumbled over his words, rushing out a quick “Thank you, so sorry!” to the young man in front of him before rushing to the room, ignoring Hawks’s whistle as the door shut behind them.

Their sidekick assignments sat on the table; when Izuku turned his sheet over, his heart sank.

“Were you hoping for someone else?” Best Jeanist asked, his brow furrowed as he looked over Izuku’s shoulder.

“I… no, no. Nothing to do with this,” Izuku said, his energy dissipating as his thoughts wandered back to the intriguing Bakugou that was waiting outside that very room.

A new sheet of paper fell in his lap, with that very name typed across it. Looking up, Izuku caught a flash of red before he realized his own assignment sheet was gone.

“Hawks!” Izuku shot to his feet, waving his paper around. 

The young hero waved him off. “Our assignments got switched around at the last minute. Simple mistake! Don’t keep your new sidekick waiting, Midoriya!”

Bakugou Katsuki — Quirk: Explosion

One Month Later

With a cheerful smile on his face, Izuku waved off the squad car holding their latest catch. He heard a fresh wave of shouting and clamoring to his left, and when he turned, he spotted blonde spikes in his periphery. His new sidekick was definitely quite popular with citizens across the city, despite his aggressive demeanor. Kacchan definitely had his own niche kind of charm that attracted fans of all kinds, and it was that very charm that enticed Izuku to spend more and more time with the young man.

As his mentor, of course.

That was all they could be; mentor and protege, hero and sidekick, perhaps even eventually hero partners, if Kacchan — no, Katsuki, was interested. You’re getting ahead of yourself here, he silently reprimanded himself as he signed the last bits of paperwork sitting on his desk. Izuku was being improper; referring to the young man by his first name, let alone a nickname, when they’d only known each other for such a short time was incredibly inappropriate, especially given the nature of their working relationship. Bakugou-san. He needed to drill the honorific into his brain before he slipped up out loud. Thus far, he’d been able to avoid calling the blonde by anything other than his hero name. Great Explosion Murder God Dynamight — Dynamight for short. If Izuku wasn’t more careful, eventually someone would figure out he was way out of his element when it came to his sidekick.

Rising to his feet, the green-haired man stretched his arms before striding over to Katsuki’s desk to drop off his feedback from their work earlier that day. As he set down the papers, he noticed what appeared to be some schoolwork and work forms buried under the blonde’s notes from his work earlier this week, and —

“Oh no.” A pair of keys glinted at him from underneath the pile of papers. “He’s never been one to be so forgetful. And it’s already…” He glanced at his watch, sighing when he realized the agency building had been closed for the past two hours already. Jade eyes flicked across the room; not a single soul left on the floor. It seemed Izuku had two choices: drop Katsuki’s belongings off with the front desk downstairs to save him the trouble tomorrow morning when he inevitably came looking for them, or…

I’m sure they’d understand, he thought. He was doing the kid a favor, after all. Izuku could just drop off his things at his apartment, and continue on his way home after. Nothing inappropriate about that, right? Kacchan probably wouldn’t even be there, considering he hadn’t tried to call him to check if he’d left anything behind.

Grabbing the keys and sheets of schoolwork, Izuku rushed to pack up his own belongings before heading out, flashing the receptionist a toothy grin as he stepped into the cool night air. It was a good thing he’d kept Katsuki’s address written down since the week of orientation; he memorized the directions as he hopped on the bus, not wanting to over exhaust his own Quirks after a busy day of fighting villains.

When he recognized the street from his address, he got off the bus and walked down to the small building on the corner. Letting himself in through the main entrance, Izuku quickly found his apartment and pulled out the folder he’d tucked all of his schoolwork into, slipping it under the flimsy welcome mat in front of his door. As he hid the keys under the mat, a thought suddenly popped into his brain.

What if someone stole his keys, or used them to break in and rob him? Or worse, do something to hurt Kacchan?

He’s more than capable of taking care of himself, his brain said. Izuku was well aware of that, of course! But he was his mentor; his student’s well being mattered greatly to him, so why shouldn’t he take great care to ensure his safety?

“I’m sure it won’t be a problem if I just let myself in, and wait for him inside. At least that way I can make sure he gets his things back safely, and I can leave with peace of mind.” Izuku nodded to himself, already grabbing everything off the floor and tucking them in his bag.

With an ashamed glance over his shoulder, Izuku let himself in, making sure to slip off his shoes the second the door shut behind him. The apartment was dark, save for the slivers of moonlight dancing across the hardwood floors of the living room. He felt along the wall for a light switch, but instead found some hooks. Hanging his bag and coat, he slowly stepped into the room, still sliding his hand across the wall until—

“There we go.” He pressed the switch, and the large space flooded with warm light. As his eyes adjusted, Izuku inhaled sharply; emerald irises growing wide as he took in the room. His gaze bounced from one side of the room to the other, a shiver rippling through his body as his heart skipped a beat.

Plastered across every inch of the walls was his face. Forest green waves, bright sea green eyes, freckled cheeks and a wide smile. Izuku looked back at himself from every angle in Katsuki’s living room; no matter where he turned, he couldn’t escape that hero smile.

Could it really be that… Kacchan, his Kacchan, was as interested in him as Izuku was with Kacchan?

Snap out of it, his brain spat. Bakugou-san is your student, not an infatuation or obsession. Shame flooded his veins, and guilt ate away at his heart as realization competed with reason in his brain. Izuku couldn’t deny it any longer. As much as he’d tried to ignore it; as hard as he had tried to push away, to bury the impure want and lust he felt every time since he had first laid eyes on Katsuki, he simply could not hold them back any longer.

His chest heaved as that carnal hunger settled in his marrow; his lungs burning with every breath he took as he stood there, the center of his Kacchan’s attention.

In the near distance, Izuku heard the soft click of the front door unlocking. His gaze was still fixated on the large shrine of his merch to his left; stacks of half-opened boxes beneath the shelves, undoubtedly holding the latest figure and clothing releases his PR team had authorized a few weeks ago.

“What the he—De-Deku-sensei? Fuck, what—what are you doing here?” Katsuki’s voice was an octave higher than usual; the nervousness of his tone drew Izuku back. 

He spun on his heel, jade eyes locking with teary saffron pools. “I—Please, please let me explain, I—”

Clicking his tongue, Izuku held up a hand. The blonde immediately closed his mouth, stopping in his tracks. The older man’s gaze dipped down to the clothes he wore, sucking in a breath as he recognized the latest Deku merch adorning every inch of his perfect body.

“Kacchan…” The nickname slipped away from him, his infatuation seeping into the air around them as he crossed the room; each step so painstakingly slow, his heart ached when he finally stood in front of Katsuki. When the tang of sweat mixed with sweet vanilla struck his nostrils, Izuku held onto the wilting remains of his self-control.

“How long?” The question hung heavy in the space between their lips. Carmine eyes flicked between his mouth and his forlorn gaze.

“I-I could ask you the same, Sensei.”

Izuku’s mouth quirked up at that. “Not long enough.” His voice was deeper, reeking of hunger.

Katsuki’s eyebrows shot up. “You… you’re not mad, then?” The blonde’s spine straightened, his jaw ticking before a sly smirk broke across his face. “Didn’t peg you as a rulebreaker, Deku-sensei. Do the others know what you get up to when you’re not on patrol?”

His newfound confidence sparked a fresh wave of shame that washed over Izuku. What the hell was he thinking? He couldn’t follow through with this. Katsuki was his student. There were rules; morals he had to adhere to. So when Katsuki stepped forward, he stumbled backwards, shaking his head. “I-I shouldn’t have — no, no, I didn’t mean to say that, Kacch—Bakugou-san. I just came to-to drop off your things that you left behind, that’s all. I really should— oof.”

Katsuki shoved him back with ease, and Izuku fell right onto his couch. The blonde climbed onto his lap and kept his hand just above the older man’s heart, grinning wildly when he felt just how fast his heart was beating.

“Don’t lie to me, Sensei. I can see it there, in your eyes. How badly you want me; this.” Katsuki grabbed Izuku’s hand and pressed it against his half-hard cock. He groaned, screwing his eyes shut as the younger man dragged his hand up his chest, pushing against his well defined pec. “Open your eyes, I-zu-ku. Don’t deny yourself.”

God, even the way he said his given name drove him crazy. Biting back a moan, Izuku shook his head, forcing himself to keep his eyes shut. “We—we can’t do this, it’s wrong and immoral; I’m your teacher, and you—you have to be with someone your own age, Katsuki! I-I can’t, I shouldn’t, not… this is wrong, for both of us, and—”

“You’re really going to play the virtue card, eh, Sensei? Such a filthy liar…” His warm breath fanned across Izuku’s face, his tongue darting out to lick his lips. “Your cock seems to say otherwise.” Katsuki’s hand grabs his shaft over his slacks, and Izuku nearly cums right then and there. His grip is rough; his thumb pressing harshly against his throbbing tip, relishing in his pinched moans. Izuku throws his head back, shaking his head.

“Katsuki, we can’t, not like this, I-I’m so sorry, this—this never should have happened, I—”

“Kacchan; that’s what you called me earlier. I like it, Izuku. Do me a favor and say that when you cum inside of me, yeah?”

The next thing Izuku knew, there was a warm wetness engulfing his cock, a pliant tongue stroking along the vein running across the underside of it. He whimpered loudly as Katsuki swallowed him whole, gagging when the head of his cock hit the back of his throat. His eyes snapped open, a loud moan ripping through his throat at the unbecoming scene before him.

Katsuki, on his knees, with his mouth stuffed full of Izuku’s cock. Vermillion eyes wept, streams of tears pouring down reddened, puffy cheeks as the blonde fucked his face with the older man’s cock, pre and spit frothing and spilling from his swollen lips. The expression on Katsuki’s face was one of complete and utter devotion; his choked out moans and feeble gulps of air pulled Izuku under, drowning him fully in the longing he would have taken to the grave.

Instead, Izuku let himself be consumed by his burning desire. Katsuki would be his ruin; an eternal damnation he was more than content to live with.

A familiar knot grew in the pit of his stomach; Katsuki’s moans reverberated around his cock, pushing him closer and closer to the edge. Not yet, he hissed under his breath as he threaded a hand through damp blonde locks and pulled his lover off his shaft, mourning the loss of that heavenly mouth.

“Izu-ku,” he gasped, his voice hoarse. “Pl-please—”

Cupping his jaw, Izuku smiled. “I’m going to give you what you asked for, Kacchan. But I need to be deep inside of you.”

The blonde blushed deeply at his words, shoving him back against the couch cushions. Using Izuku’s knees to lift himself off the ground, Katsuki grabbed a fistful of forest green waves and tugged, eliciting a deep growl from the pro. Smiling sweetly, he whispered, “I need you to fuck me right, Izuku. In my bed…” He leaned down, brushing his swollen lips against Izuku’s. “In the same sheets I sleep in after I make myself cum, thinking of you.”

Izuku growled low in his throat, trampling over what little remained of his self-control as he lunged forward and crashed his mouth against Katsuki’s. He moaned at the taste of himself on the blonde’s tongue, grunting when he sank his teeth into his bottom lip before breaking away.

“Do you know how often I’ve dreamt of this? How long…” The blonde grabbed his wrist, and guided his hand under his sweatshirt, dragging it over sweaty skin. “I’ve yearned to feel your cock inside of me? To be stuffed, full of you?”

“Kacchan,” he breathed, his chest constricting at the lewd, earnest confession. His brain knew it was wrong; a gross, despicable thing to crave. But how could he deny himself when the heart of his fantasy wanted it just as much? Was it really so wrong? “I… I’m disgusting. How… how could you ever want… this?” Izuku screwed his eyes shut, unable to look at Katsuki as he voiced his deepest fear.

Katsuki’s mouth against the shell of his ear drew him back from the darkness clouding his mind, his hot breath fanning over it sparking gooseflesh across his skin.

“You’re the most beautiful thing I’ve ever laid eyes on, Izuku. How could I not want you? How could I not want someone as strong, incredible, and kindhearted as you? You’re leagues above any other person out there. I only want the best and, even if everyone else says it's wrong, I know you’re the best there is for me. I’m yours, in whatever way you want me.”

The sincerity in his words brought tears to Izuku’s eyes. His words caught in his throat, his brain unable to produce anything other than a simple “My Kacchan.” 

The blonde nodded, smiling softly as he pressed a chaste kiss to the older man’s jaw, tugging on his hair again.“C’mon, Sensei. Need that fat cock of yours, now.” 

Izuku blushed at his forwardness, making a mental note to poke around his brain later for his thoughts on his own… performance.

They barely made it past the threshold of Katsuki’s bedroom before they were tearing each other’s clothes off, the blonde’s hole winking at Izuku as he pressed himself into the mattress, his ass high in the air.

“All for you,” he teased, his taunting giving way to wanton moans the moment Izuku licked over his taint. Sliding a finger across wet skin, the two men groaned in tandem as Izuku circled Katsuki’s puckered rim, his hole fluttering and desperate to be filled.

Completely awestruck, Izuku decided he couldn’t hold back anymore. The green-haired man grabbed his cock and smeared his piety over the aching head, then rubbed it over Katsuki’s gaping hole. The blonde moaned out his name, arching his back sinfully, and pressing his face into his rumpled sheets.

Grabbing Katsuki’s hip, Izuku hollowed his cheeks and spit at the junction where his cock kissed that perfect, swollen hole before snapping his hips and bottoming out in a single thrust. 

“Fuuck!” his lover screamed, reaching blindly behind him as his sensei, a madman, set a brutal pace. Digging his fingers into the supple flesh of the blonde’s hips and ass, Izuku marveled at the bruises he began to leave behind as his hands roved over heated flesh, wanting to touch and mark every part of Katsuki within his reach.

It was better than anything his mind could have conjured up; the warm, intoxicating tightness around his cock, the way his asscheeks bounced against his hips, the harmony of Katsuki’s cries and the schlick of his drenched cock fucking in and out of him. Izuku would never get enough of it; he’d go stark raving mad if he could never feel the inviting warmth of Katsuki squeezing around him as he slammed into his sloppy hole, or if he could never hear his muffled screams for more, fuck me harder, Izuku, please echoing in his ears.

Another babbled plea echoed loudly over the quickening beat of his heart as the green-haired man leaned over the blonde’s back, sinking his teeth into his shoulder.

“Iz—Izuku, fuck,” Katsuki sobbed, wriggling his hips in a pathetic effort to meet his erratic thrusts.

Izuku hummed, tongue smoothing over the indentations of his teeth in soft, pale skin. “You feel so— fuck — so fucking good, Kacchan. Like this hole was made just for me,” he hissed between clenched teeth as Katsuki’s walls clamped down on his cock at the praise. Each and every sensation was overwhelming; Izuku swore he was growing more delirious with every jerk of his hips, the feeling of his lover’s rim sucking his cock in pushing him closer and closer to the brink of utter ruin.

“All for you, Izu — nngh,” The blonde whimpered as Izuku left a sloppy trail of kisses and love bites across his back, his hands gripping his hips like a vice. Every harsh thrust shoved Katsuki deeper into the mattress, his knees slowly giving way as he struggled to hold himself up.

“Please, I—I’m so close, I—” the blonde keened, pushing back on the green-haired man’s cock, chasing after more. Battle-worn fingers wrapped around the blonde’s useless shaft, stroking the swollen head in time with every snap of Izuku’s hips.

“You sound so pretty like that — begging for me. Be a good boy…” Thick fingers knotted themselves in blonde tresses and tugged, bringing Katsuki flush against Izuku’s chest. “And take what’s yours, Kacchan.”

With one final, brutal thrust, the blonde cried out, hands clawing at the messy sheets as thick ropes of cum streaked across the bed; his spurned cock twitching from the aftershocks. Katsuki’s walls squeezed Izuku tightly, unraveling the knot in his stomach as wave after wave of pleasure crashed against him. Izuku came with a loud growl, his face buried in the blonde’s throat, teeth nipping at the sensitive skin as hot spurts of white coated every inch of Katsuki’s insides.

Boneless, sated bodies collapsed onto soiled linens and entwined, forgoing any clean-up for the sake of closeness. Katsuki fit perfectly against the contour of Izuku’s frame; his head tucked neatly against the base of his throat, and his ass pressed firmly against his half-hard cock.

They stayed like that for quite some time; Katsuki’s breathing evening out rather quickly, his fingers threaded between Izuku’s as he slept. Despite the domesticity of it all, Izuku’s anxiety spiked as they laid there in the wetness of their desire’s consequences.

There was no going back now; Katsuki was his, as he was Katsuki’s. How would they explain this to the agency? To his teachers? To his own colleagues?

“Your brain is so loud, I can hear it from here.” 

Izuku’s gaze fell and was greeted by wistful saffron eyes. They crinkled at the edges as the blonde smiled tenderly, reaching up to cup the older man’s jaw. “Don’t worry, alright? We have the rest of the year left before I graduate. It shouldn’t take much to convince you to start an agency with me after, right?”

Izuku’s heart fluttered. “B-But, Kacchan, we—” Katsuki slapped his hand over his mouth. Jade eyes grew wide.

“Izuku, you had no idea I was obsessed with you. You really think I won’t be able to get away with us being together?” The green-haired man shook his head. Katsuki sighed. “Tch. We’ll figure it out as we go, okay? You think you can handle that?” 

Izuku nodded.

When Katsuki moved his hand, Izuku took it in his and kissed the back of it, emerald irises flicking up to meet adoring vermillion as his lips lingered against his soft skin. “Don’t think I’m going to let your little obsession slide, Kacchan. You still haven’t answered my question.”

With a sly grin on his face, Katsuki gently pushed Izuku onto the bed, straddling his waist as he took his hands and placed them on his hips. The older man moaned when the blonde’s ass rubbed against his cock, the traitorous thing hardening at the slight friction.

Amused, Katsuki said, “Since I was fourteen. Always got off to your voice during interviews…” The blonde grabbed Izuku’s cock and nudged his leaking head against his entrance, moaning softly. “Fuck me even harder this time, Sensei, and maybe I’ll show you the Deku dildo living in my nightstand.”

Bucking his hips, Izuku’s cock slid inside of Katsuki with little resistance. The blonde gasped, pouting ever so slightly when he laughed. “You won’t need that anymore, Kacchan.”