In all honesty, he didn't even know when it had started.

Sports festival, probably. Well, actually the sports festival had only made clear what he'd already suspected since...since fucking day one.

The little shit was a fucking ray of sunshine from beginning till end, and even Katsuki himself hadn't stood a single chance against him. From the time they were children all throughout middle school, Katsuki had been struggling with the fact that someone as weak and shitty as Quirkless fucking Deku had that big of a hold on him- without even fucking knowing it.

To this day, he still hadn't decided if that last part was a good or a bad thing.

Point was; Katsuki was crush- wait, no, fuck that. That word sounded so fucking girly. Katsuki didn't fucking crush on people. He crushed them, yes, but never in his life did he crush on them. Whatever the hell he was feeling for that damn nerd wasn't a crush. An infatuation, at most.

Either way, it'd been a pain in the ass, and Katsuki had decided on just completely forgetting about it.

A plan that he'd thought would work pretty well in his middle school years. Ignore Deku, and scare him away enough for him to keep his distance for good, and hopefully take these damned unwanted feelings with him in the process.

It didn't work.

As horrible as it was, Katsuki's scaring tactics had worked perfectly- too perfectly. Instead of making him completely forget the damn nerd even existed, it had him constantly thinking of the bastard.

Did I go too far today?

Deku had been crying a shit-ton today, but he's always quick to cry so it doesn't matter.

Shit, he looked beat up.

It were thoughts like these that had always been nagging somewhere in the back of his mind, and many times they'd made him stop his tormenting for a little while before he ultimately decided fuck it, and started where he'd left off.

Because during each of his 'breaks', his thoughts would still be occupied with Deku. In ways he definitely didn't want.

So, he'd settled on being his regular unapproachable self and keep the damned cute- no -nerd at a more than respectable distance; the thought of quitting this entire, toxic system always camping somewhere fresh in his mind. It wasn't the most ideal choice, but it had to do. Especially since he didn't want his brain filled with thoughts of Deku's distracting face and little freckle- Jesus.

It hadn't lasted as long as he'd initially hoped. The incident with the sludge monster had been the final straw.

Deku's expression, rushing to his aid while having a 70% chance of the idiot getting himself fucking killed... Katsuki couldn't get over it. Especially since his only damn reasoning had been: 'You looked like you needed help.'

Fucking idiot.

Because Deku was fucking Quirkless and weak and goddammit Deku, can't you fucking realize I am supposed to be the one protecting you?!

He was the one with the ridiculously powerful Quirk. He was the one supposed to save his dumb ass. Not the other way around for fuck's sake!

Why didn't he fucking get that?

In the end, Katsuki had given in to his consciousness. The one that had been nagging at his brain for God knows how long. He'd left Deku alone.

It was around that time that he'd realized irony was a fucking bitch. Because guess what? Thoughts of Deku? Weird feelings stirring up inside him whenever his name was mentioned? Whenever he fucking saw him or heard his shrilly-ass voice sounding nearby?

Gone.

All. Fucking. Gone.

Though now that he looked back; they'd never really disappeared. Just stayed suppressed until his time at Yūei.

Yūei was the point where it all went to hell.

Izuku hadn't heard from him in a while now.

Call him masochistic, but he'd actually missed the countless calls of "DEKU!" whenever he merely walked the hallways. He wasn't particularly fond of everything that usually came after, and, he wouldn't lie, he was glad that he wouldn't (really) have to deal with all the constant bullying anymore.

But the sound of Kacchan calling out his name? That was a sound he would never want to miss.

Though...not like this.

It'd taken him a while before he'd finally mustered up the courage to knock, but of course Kacchan had to beat him to it. The door swung open, and Izuku tried not to flinch as his childhood best friend glowered in the doorway. He also tried not to stare too much, even if the way that black, formfitting tanktop of his was... positively distracting.

God, he was going to hell.

"K-Kacchan!" he squeaked, feeling a lot more jumpy than usual.

Katsuki stared at him, crimson eyes boring into his skull, and Izuku swallowed. Oh boy, he seemed agitated- uhh, more so than usual, he meant. Izuku couldn't blame him, he'd be pretty miffed too if he was stuck with someone he hated for a school project.

"Team Bonding" All Might had called it, but the both of them knew it was just another excuse to put the two of them together; in hopes of them settling out their differences. Not an entirely futile attempt, but still pretty far-fetched. They'd gotten somewhere, but they were far from reconciling and becoming friends; let alone go back to the way they used to be.

Izuku didn't like that thought. It was realistic, but it brought a pang to his chest.

After a few seconds of silence, the explosive boy growled and disappeared into the hallway, a slight color to the tips of his ears. He left the door open; which was Kacchanese for 'hurry the fuck up and come in already.'

And with a low sigh, Izuku followed in after.

He'd expected lots and lots of yelling upon his entrance, since he remembered Kacchan's mother having a personality just as explosive as that of her son's, but nothing happened. Instead, he walked into the living room to find the blond with his back turned to him; defined muscles carefully crafted into his skin and a mountain of books scattered on the coffee table, several of them lying open on random pages. Kacchan had already started, it seemed.

"The old hag isn't here, if that's what you're thinking." Katsuki murmured, heading towards the kitchen. Izuku followed him with his eyes, awkwardly standing in the center of the room as he did so and watching how the other grabbed a bottle of water from the fridge. "She went out with my dad." He unscrewed the bottle cap, still refusing to make eye contact as he took a sip. "So let's get this over with so I can get back to fucking sleep."

Izuku tried not to roll his eyes. Typical.

"U-uhm, yeah," he cleared his throat, the awkwardness of this entire situation nearly suffocating him. Izuku decided that, as ecstatic as he was to be able to spend time with Kacchan that wasn't 90% yelling (yet), if things went like this, he preferred spending the evening cuddled in his room; watching an All Might DVD he'd seen three-hundred and seventy-eight times before, to be precise. "Let's."

Katsuki's eyes were dark as he jumped over the back of the couch and landed on the cushions with practiced, yet natural movements. His muscles tensing oh so distractingly beneath the skintight piece of fabric covering his chest. At least the sweatpants he had on had mercy on him.

"Are you just going to stand there all day like a fucking idiot or are you actually going to get your ass over here?!" Katsuki snapped. As Izuku got pulled out of his inner, perverted thoughts- (oh God he was turning into Mineta) quite rudely, he might add -he noticed a few things.

One, Kacchan had a book in hand, lazily flipping through the pages.

Two, his sharp, red eyes- as discreet as they might be -were watching him impatiently. It was just a sideways glance, waiting for him to actually do something, so Izuku probably shouldn't be looking into it all too much. But he could see- or thought he could see -a couple of different emotions swirling into those unfairly mesmerizing orbs.

Irritation was the most obvious one, though that was a given.

Then there was...curiosity, a hint of a challenge, and- yeah, no, that last one was definitely a mistake.

"Y-yeah, I, uhm-" he hesitantly moved closer to sit beside him. "Sorry," he finished, quite lamely, trying his best to push all (sinful) previous thoughts out of his brain.

Because to him, it'd looked like Kacchan had been giving him bedroom eyes.

Shaking the thought from his memory, Izuku worked on unpacking his backpack. He only had the essentials on him- books, pens, markers -so it wasn't really the most time-consuming task, but it certainly was enough to distract him for the time being.

Meanwhile, Katsuki- the cause of all his distractions -leaned back against the couch with a low, irritated growl of 'fucking Aizawa'. He'd stuffed his hands into the pockets of his gray sweatpants, a black sharpie held between his teeth, and Izuku had to remind himself that hey, air was great, and he should probably try breathing again; cause breathing was important and crucial, if he ever wanted to make it into the hero business.

The hour that followed after had been filled with the two of them reluctantly working together to finish this forced duo assignment as soon as possible. Mainly because Katsuki obviously didn't want him there- his face seemed to be getting increasingly redder the longer he sat close to Izuku, his jaw clenching -and Izuku didn't think it was healthy for him to have to remind himself to breathe every other ten minutes.

They'd divided the work quite nicely, with Katsuki doing research and Izuku writing everything down, and then switching after thirty minutes because "looking useless shit up was fucking boring", but they managed.

It wasn't until Izuku started mumbling that things took a surprising turn.

They'd been busy for quite a while now, and it'd gotten to the point where Izuku had to wonder if Aizawa and All Might hadn't purposefully made this a time-consuming assignment in order to keep the two busy- and, in turn, together, -for a much longer time than initially planned. He wouldn't put it past them.

Katsuki had vocalized his complaints numerous times over the past three hours, with the occasional "Damn useless teacher" and "I'll fucking kill them all" thrown into the fray, just for good measure.

There were also some "Deku, work faster, damn it" or "Hurry the fuck up, you damn nerd!" And there was that one time where he'd yawned and let his head drop back against the couch, murmuring a soft "Deku, what time is it?" with no yells, curses or insults whatsoever; though that might've just been due to sleep deprivation.

Izuku risked a glance at his 'partner'. He was busying himself by repeatedly tossing the thick black marker up in the air and catching it without even bothering to look; his eyes occupied with scanning through one of the numerous books scattered across the table. He looked tired, and Izuku decided he had to work even quicker so they could get this done and his one-sided crush wouldn't have to show up to school in an even worse mood than usual from lack of sleep. Of course they could just always call it a day and part ways for tonight, but Katsuki had made it pretty clear that he wasn't willing to spend more than one night on this project together with him.

Izuku bit the insides of his cheek. Ah, there it was again, that painful pang running through his chest.

He took a look at the printout Aizawa had handed to them- and the rest of the class -the previous morning. Introduction, basic hero tasks, everything they'd learned up till that point...

His eyes caught on the last word.

"Hero analysis, huh?" Izuku mumbled, his mind already kicking into overdrive. All of his obsessively kept notebooks were still on his bookshelf back at home, but he was pretty sure he's read through all of them so many times that he knew them by heart. "Let's see...pick three pro heroes of your choice and research them based on Quirk, basic skills, special moves and any other topics worth mentioning."

All Might was a given, considering both him and Kacchan admired him the most (even if the latter had a nasty habit of denying it), but that might just prove to be a difficult task to pull off, if you took into account that All Might's Quirk was supposed to be secret. Izuku wasn't supposed to know anything about it, so maybe he could try and brush over that particular topic without seeming too suspicious.

Ingenium was another interesting hero to tackle, though that might just have a bad effect on Iida...

Maybe-

"Deku."

"Hm?" Izuku looked up, only for his heart to stop completely and then do a somersault as Katsuki leaned in and captured his lips with his own.

The kiss was different from what he'd expected- not that he'd ever expected Kacchan to actually ever kiss him.

Instead of a rough, sloppy and lustful open-mouthed lip lock, all he got was a soft, gentle, almost caring pressure to his lips and Izuku almost melted into a puddle then and there. Especially when the blond brought his hand up to place it on the other's cheek, only pulling him in closer.

Finally, he pulled away, and all Izuku could do was gasp out a strangled. "Ka-Kacchan."

"Your rambling's irritating," he said, his tone soft and his eyes lidded. Katsuki stared straight at him, and Izuku could already feel the heat of his reddened face rushing all the way down to his neck; and possibly his torso.

Izuku nearly choked. "Wh-wha- you-you just-"

He rolled his eyes. "Deku," he crooned, moving closer. Instinctively, Izuku moved back, until his back was pressed flat against the surface of the couch and Katsuki was looming over him; those pretty, crimson eyes staring straight into his green ones. "I just fucking told you to shut up."

Izuku swallowed. No way. There was simply no way that this was actually happening. "Kacchan-"

Katsuki scoffed. "You really don't fucking listen, do you?" he leaned in closer, face burying into his neck, and Izuku shivered at the hot breath brushing against his skin. "Damn nerd."

Izuku's mind was a haze. He couldn't figure out for the life of him what was going on, and whether or not this was real life or he was just stuck in one of his overly realistic dreams. It was just too good to be true, and he had to bite his lip to the point of drawing blood when Katsuki started trailing his lips down his collarbone.

"K-Kacchan, wait!" he gasped, managing to find the will to grab onto his shoulder. Katsuki didn't say anything, but froze in his movements; his way of saying 'what?!'

Izuku swallowed, debated whether or not he was actually going to go through with this, and then decided that yes, he was, because it was the right thing to do. "Kacchan, you- you're- you're sleep deprived. You probably don't-"

He bit down, and everything that Izuku had been planning to say dissolved into a whimper.

"I'm not doing this because I'm fucking tired, Deku." he snarled, and Izuku swallowed again. He'd hit a nerve. "Use your fucking brain."

"B-but-"

"Nothing," he interrupted, pushing his weight onto his arms to hover over Izuku's smaller frame. His eyes were deadly, cold, and the green haired hero in training realized that yeah, he'd messed up. Big time. "But nothing."

"Kacchan-"

"Let's get back to work," he growled, climbing off the other boy and returning to his earlier seat. He made a point of grabbing a textbook- quite violently -and flipping through the pages in a way that risked tearing them.

"Kacchan, listen-"

He ignored him. "We're almost done, aren't we?"

Izuku hesitated, then nodded. "Y-yeah, only one more question left."

"About fucking time."

Izuku kissed him.

He won't lie, he was freaking terrified of Kacchan's reaction. He already seemed pretty pissed, and for all he knew, what'd transpired only seconds before was all a ruse. He might just be ruining everything they'd been working to build up in this past year, but he'd take his chances.

The sigh of relief that escaped him when Katsuki started kissing back was enough to have the blond's lips curling into a slow, satisfied smirk.

He pushed Izuku down, climbing back on top of him as he deepened the kiss; this time forcing his tongue in to explore the other's mouth. The surprised little gasp Deku gave him was just delicious, and Katsuki decided that there was no way he could stop now.

After all, they still had the entire night ahead of them.