Archive of Our Own ^beta

It started small, as these things often do.

Izuku has always had a penchant for noticing Katsuki’s…well, everything. It was one of those indisputable facts about Izuku: he was kind of weird, and he had a staring problem, and he was obsessed with all things Bakugou Katsuki. 

Was Kacchan aware of this? …maybe? Debatably? Izuku didn’t really know—mostly because he was afraid to ask—but Katsuki wasn’t by any means unintelligent, so he probably noticed and was just ignoring it for Izuku’s sake. He didn’t really want to think about any alternative. 

The point was that he knew everything there was to know about Kacchan, and one of these things was that he doesn’t like to be touched. 

Or maybe Izuku should amend that statement, because now it’s more like he doesn’t touch Izuku. 

Izuku remembers very little about their childhood together before Katsuki started hating him. They were so young, too young, so most of what he knew about it was through pictures and stories from his mother. Inseparable she had described them as, her voice lilting with nostalgia that made Izuku ache in ways he couldn’t even begin to explain. But even though it was foggy, one thing Izuku could never forget was that Katsuki always held his hand. 

So his dislike of being touched didn’t start there. It was more like, after he got his quirk, and he got mean, and Izuku became Deku and he never got to hold that hand again. No matter how much he longed for it. 

Izuku had hypothesized though, through weeks of observation (shut up, it’s not weird) that this touch aversion he developed was another defense mechanism to add to his angry persona, as he didn’t let anyone touch him anymore. 

Izuku was nothing if not a man of science. He liked making observations, hypothesizing, performing experiments to test the validity of his theories, and coming to conclusions only based upon the facts he had—no feelings involved.

(He’s lying a bit here. With Kacchan, there are always feelings involved.)

But now though, his proven theory was starting to become invalid. And so, Izuku does what he does best.

Studies his favorite subject. 

And so, it does start simple. Izuku walks into the common room one afternoon with Ochako, and finds Kacchan with his friends playing video games on the couch. Which would be normal except he’s laid out on his side, leaning against Kaminari, and his socked foot is kind of tapping Sero on the shoulder kind of.

Izuku stops short, blinking rapidly, because the Kacchan that Izuku knows would never allow this kind of contact. Except it's happening and it seems to be his doing, if the stupefied expression on Kaminari’s face is any indication.

And Kacchan is just…playing the game like everything is normal, eyes narrowed and focused and tongue kind of poking out in that adorable way it does when Katsuki really gets into something, and so clearly he doesn’t mind it. Like at all. It does something funny to Izuku’s insides.

“Deku, you coming?” Ochako calls, snapping Izuku out of whatever trance he was in, and making him realize he was just standing there, staring like a creep at Katsuki being affectionate with his friends. She also calls Katsuki’s attention to Izuku, his head snapping up to meet Izuku’s gaze.

But he doesn’t look mad. No, if anything he seems…relaxed and almost happy ? There’s this little smile on his face and his eyes, although burning ( always burning) are soft and warm, and Izuku tries to will the heat on his face to dissipate. But it's a fruitless attempt of course. How can he not fluster when Kacchan looks at him like that?

“Hey, nerd,” Katsuki says softly, and maybe Izuku is just imagining it but he somehow makes the insult sound…nice? Endearing?

Christ. The delusions are crowding his brain and removing all intelligent thought. 

“Kacchan! Hi!” It’s shrill and embarrassed and the way Izuku’s voice cracks makes him want to fall into a hole and never come back up. “I wasn’t doing anything!”

He…doesn’t know why he said that. He has no fucking idea. Kacchan’s brow furrows and he gives him this confused look, and again where is that hole? Izuku would like to jump into it now, if possible. 

“ I mean—uh. I’m gonna–I gotta go. Bye!” He turns around and hightails it to Ochako, who’s waiting at the bottom of the stairs for him, amusement painted across her features. Izuku’s face gets pinker.

“Shut up,” he huffs. 

“I didn’t say anything,” she points out, but that smug grin says it all by itself. Izuku doesn’t say anything more, but the image of Kacchan stays burned into the backs of his eyelids. 

The next time it happens Izuku walks in while Katsuki is making dinner for the class (which he will vehemently deny doing if asked) and talking quietly with Mina—as quiet as he can get, anyway. She’s perched on the counter next to him, swinging her legs and Katsuki is stirring a large pot with the ease that comes from habit.

Izuku hesitates in the doorway, caught between staying and leaving when Mina says something that makes Kacchan laugh. Not that sharp, biting cackle he defaults to but an honest-to-goodness actual laugh and it's warm and golden and turns Izuku to goo.

His chest tightens, the sound so lovely it almost hurts to hear it. And then–and then— Katsuki ruffles her hair. 

Izuku swallows his jealousy, which feels suspiciously like swallowing glass, and tries not to think about how he would beg Katsuki to do the same with Izuku.

The third and final piece of evidence comes when the bell rings for lunch the next day. Kacchan’s friends all crowd around his desk like they usually do, and Izuku pretends not to watch Katsuki’s every move while he packs up his things. Kirishima says something, and Katsuki lets out this quiet snort and little happy grin (and Izuku dies inside, just a little bit) and swings his arm around Kirishima’s shoulder, dragging him out of the classroom with the rest of the group following behind. 

And they’re leaning so close and Izuku, well. He stays behind, staring at his desk and he longs . So badly to be the one Katsuki touches casually like that. And he thinks, what’s the harm? They’re friends right? In the same way him and Kirishima were friends…or well, maybe a little different, a little better—

No. Stop that, Izuku! He takes a deep breath, and lets the jealousy go, and reminds himself that Kacchan is not his to keep and to have and to hold forever —

Anyway.

Him and Kacchan were friends. So if Izuku were to…give him a hug, or lean on him or something it should theoretically be fine, right? 

Well. There was only one way to find out. 

And so, the experiment begins.

The basis of a proper experiment involves four parts: the independent and dependent variable, the control and experimental group. 

Izuku’s hypothesis is as follows: Kacchan likes touching people now, so it should be fine if Izuku starts touching him too. The control group would probably be Kacchan’s friends. Mina, Kirishima, Kaminari, and Sero who Izuku has already seen touch him before with positive results. His experimental group was obviously himself. 

The independent variable? The actual act of touching Kacchan.

The dependent variable? Kacchan’s reaction.

It was a foolproof plan.

Or, well, almost foolproof.

“Deku,” Ochako says slowly when he shows her his whiteboard covered in almost illegible scribble, photos of Kacchan that Izuku had sneakily taken when no one else was looking, a bunch of arrows and a giant title. Operation Kacchan.

Izuku thought it was fitting. 

“You don’t think this is a little…”

“Obsessive,” Tenya volunteers from his seat in Izuku’s desk chair. 

“I was going to say stalker-y, but that also works,” Ochako says, standing to get a closer look.  She points to a photo of Kacchan, shirtless and benching three hundred fifty pounds. “Why did you need pictures of him in the gym?”

Izuku looks at it again. Stares a little. It’s a really nice picture. “For science!”

“I think it’s nice,” Shouto says from his seat on the floor. He’s eating spicy chips and getting crumbs all over Izuku’s carpet. 

“Thank you, Shouto,” Izuku exhales. At least someone understood. “It’s not creepy at all!”

“I didn’t say that,” Shouto tilts his head like a confused puppy. In some ways, he kind of is. “It’s actually very creepy, but this is pretty normal for you.” 

“What is that supposed to mean?”

“It means that your crush on Katsuki manifests as obsessing over him and stalking him in your spare time.” 

Izuku blanches. Tenya’s lips go very flat, like he’s trying to hold in his laughter. Ochako just flat out laughs at him.

Shouto blinks. “Did I say something wrong?”

“No, honey, not at all,” Ochako says, mirth still in her voice as she ruffles his hair. “That was a great read.”

“Read?” Shouto looks up at her, “Like a book?”

“No, Shouto, it’s like,” Izuku sighs, trying to explain and sort of coming up short. “I don’t know how to explain. It’s a figure of speech.” Trying to explain expressions to Shouto was going to make Izuku’s brain hurt. 

“The point is that you don’t need to treat this like an experiment,” Ochako says, “You and Bakugou are friends, right? “You could just, I don’t know, talk to him like a normal person.”

“Do you know who we’re talking about?” Izuku gestures wildly toward the board, as if the photos of Katsuki scowling at various angles would make his point for him. “Kacchan is not a normal person! He’s…he’s Kacchan!”

“Wow, compelling argument,” Ochako deadpans.

“Seriously, Midoriya,” Tenya says, folding his hands in that overly formal way of his. “Communication is the foundation of any healthy relationship.”

“Yeah, because he’s so good at that,” Ochako rolls her eyes. “Considering he’s been hiding a crush for over a decade.”

“Was that sarcasm?” Shouto asks.

“Yes, it was,” Ochako grins, “Good job, Sho!” She holds out her hand for a high five and after a moment, Shouto remembers what he’s supposed to do and slaps it with his own. Sarcasm was another thing that he struggled to get at first. But Ochako uses it enough that he’s starting to catch on.

“Can you guys stop bullying me,”  Izuku sinks into his chair, his head in his hands. “This is research. Science. You can’t just rush into something like this without data!”

“I still think that you need to just speak to him about it,” Tenya sighs. “But if the experiment will make you feel better then I suppose it’s harmless.”

“Boys like you are the reason why I’m bi,” Ochako rolls her eyes, “Let us know when this blows up in your face.”

“It won’t,” Izuku huffs. “And I will be reporting back all the results for proof.” 

Izuku realized two things almost immediately after setting his experiment into motion.

One: It was significantly harder to find a natural opportunity to touch Katsuki than he had anticipated. Mina could lean against the counter, Kirishima could throw an arm over Katsuki’s shoulder, and Kaminari could all but drape himself across Katsuki’s lap during video game marathons without so much as a second thought.

But Izuku? Izuku couldn’t even stand too close to Katsuki without feeling like his skin was on fire. His palms would sweat, his heart would race, and his brain would go utterly blank at the prospect of initiating contact.

And two: The more Izuku tried to touch Katsuki, the more he realized that Katsuki was hellbent on not touching him at all. 

Izuku and Katsuki were close (and it wasn’t just his delusions talking) and they hung out a lot. So Izuku assumed that it would just be easy for him to just…do it. At least two or three times a week they had one on one hang outs. Sometimes, they would study together in Katsuki’s room, sitting at the kotatsu table in the middle of the floor. Izuku would help Katsuki with English, and Katsuki would tutor him in chemistry. And they’d sit so close, virtually side by side at the table, but never touching. Izuku wasn’t sure if it was his own doing or Katsuki’s but he was going to bridge the gap regardless. 

When they sit down, Izuku sits closer than he normally does, close enough that he practically feels Katsuki’s body heat radiating off him. This is good, Izuku thinks as Katsuki takes off his uniform jacket. He was still too nervous to do intentional touches, but this way their arms would casually brush, and maybe they would even play footsie under the table! 

Except, when he puts his arm up to write, and their shoulders brush. And the second a point of contact is made, Katsuki freezes and shifts away from him. Subtly, so much so that if Izuku wasn’t hyper aware of every movement he made he wouldn’t have even noticed. But he scoots, just a little to the side, so that they can’t touch at all.

And Izuku…well, he tries to dismiss it as just Katsuki needing space to work. So he pretends to be engrossed in his math problems and ‘unintentionally’ nudges Katsuki’s foot with his own. Kacchan draws both his knees up and continues working like nothing happened. Izuku pretends that it doesn’t burn. 

For three days, Izuku tries to find the perfect moment, but it never comes. He observes Katsuki more, thinking maybe he’s drawn back into himself? But no, he still lets Mina hold his hand while they walk to class, still gives Kirishima pats on the head or back, still leans back on Sero’s legs during movie night and plays footsie with Kaminari when he tutors him in the common room.

And it’s not even just his close friends. 

Katsuki briefly joins girls night in the common room to help Momo brush her long hair and braid it into a fishtail. He punches Todoroki lightly on the shoulder when he beats Kacchan in spades for the first time. He even hip bumps Jirou when his hands are full and she’s blocking the entrance to the kitchen. 

Kacchan touches everybody casually. 

Everyone except Izuku.

On their bus ride to the USJ, Kacchan sits next to him and actually engages him in conversation. Izuku takes a light nap on his shoulder, but wakes up with his head pressed against the window. He taps Katsuki on the shoulder when he’s in the kitchen with his headphones on, and he flinches like he’s been burned. Even when they spar, Izuku realizes that Kacchan only makes direct contact with him when absolutely necessary, and stops immediately when they’re done. Every time Izuku got close enough to act, Katsuki would shift, dodge, or glare just enough to make Izuku retreat.

It made him feel…well, this was an experiment., so the way Izuku felt didn’t really matter. So if we deal in cold hard facts, then we have three. 

1. Kacchan liked physical contact.
2. Kacchan made physical contact with their whole class on a regular basis (averaging about 5-6 touches initiated a day not including the ones where others touch him first. And no, it's not weird that Izuku counted)
3. Kacchan refused to touch or be touched by Izuku

“I think he hates me,” Izuku groans into his pillow after four days and more scribbles on the whiteboard. He switched to a red marker to signify his horrible mood. 

“He doesn’t hate you,” Ochako sighs, but when Izuku looks up at her, she has this worried look on her face like she doesn’t quite believe it herself. Izuku flops back into the pillow and tries not to cry.

She runs his fingers through his hair in what's supposed to be a comforting gesture, but all Izuku can think about is how he wants it to be Kacchan.

“He definitely doesn’t hate you,” Tenya agrees, “If he did he would have said so. Repeatedly. Bakugou doesn’t seem like the type to mince his words.”

“He always says he doesn’t do things he doesn’t want to do,” Shouto adds. “So if he didn’t wanna hang out with you, he wouldn’t.”

“You guys don’t get it,” Izuku sighs, rolling over to stare at his ceiling. All Might stares back at him. Izuku really needs to change his decor; this is not comforting at all. “What if he’s just forcing himself to hang out with me because he feels bad?”

Even after that apology all those months ago, Katsuki still acted like he had something to atone for. He had expressed to Izuku later that he wasn’t done making up for it. What if he was only doing this because he knew Izuku wanted it. What if he knew about Izuku’s devastating crush on him, and was just humoring him instead of letting him down easy?

“Again, Bakugou would never do that,” Tenya enforces, raising an eyebrow. “I think this is all just a misunderstanding. I’m sure if you talked to him, it would all be fine.” 

“Not doing that,” Izuku huffs childishly. What the heck was he even supposed to say? Hi, Kacchan, can you please touch me? I’m in love with you and I want your hands on me and it's making me insane.

Yeah, right. Izuku would actually die of embarrassment. 

Shouto raises a hand like he’s in class. “Maybe you could try making Katsuki jealous. I’ve read that it's effective in certain romance novels.”

“Jealous?” Izuku repeats, horrified. “Of who?”

“Me,” Shouto says simply, like it’s the most obvious thing in the world.

Ochako bursts out laughing so hard she nearly falls off the bed. Even Tenya lets out a choked sound of disbelief.

“Shouto, I—I don’t think that would work,” Izuku says, frantically waving his hands. Besides the fact that Izuku is a terrible liar and an even worse actor, Katsuki would never be jealous.

“Why not? I’m very desirable.” Shouto pops another chip into his mouth, utterly unbothered.

Ochako is wiping tears from her eyes at this point. “Oh my God, Shouto, you’re a menace. Please stop giving Deku bad ideas. He’s already on thin ice with the gym photos.”

“I needed those for reference!” Izuku insists, his voice cracking.

“Reference for what, your daydreams? Or your night ones?” Ochako teases, winking.

Tenya clears his throat loudly, clearly trying to restore order. “The point remains: Izuku, this situation requires courage, not subterfuge. You cannot let fear dictate your actions.”

Izuku groans again, slumping forward dramatically. “I don’t know why I told you guys anything.”

“Because you love us,” Ochako says cheerfully. “And because we’re the only ones who’ll put up with your nonsense.”

And so, Izuku is left with no choice. He has to…communicate. Ugh. He’s a seventeen year old boy for christ’s sake! He’s pretty sure that’s against the rules, or something.

It’s with that reluctant resolve—and about three hours of pacing in his room—that Izuku finds himself knocking on Katsuki’s door. His knuckles barely graze the wood before the door flies open, and there Katsuki is, scowling, but his face softens when he sees Izuku. Marginally, but enough to calm Izuku’s nerves, just a little.

“The hell do you want, nerd?” Katsuki snaps, but his voice lacks bite. From anyone else, it would probably be rude, but from Katsuki it was just his default setting. He’s in sweatpants and an old tank top, hair sticking up even more than usual.

Izuku fidgets. “Um…do you wanna watch a movie?”

He doesn’t know why he said that. He was supposed to ask to talk. But rehearsing it to himself in his room was way different than standing before Katsuki in all his beautiful, muscly glory, and he’s giving him that look again, and Izuku can’t think straight. 

Katsuki raises a brow, leaning one shoulder against the doorframe. He studies Izuku for a moment, and he tries not to shiver under that burning gaze. Then he shrugs and steps aside. “Whatever. But if it’s some dumb hero documentary, I’m kicking you out.”

Izuku nearly trips over his own feet in his haste to enter, heart pounding. This isn’t unusual—they’ve hung out like this before—but with everything swirling in Izuku’s head, it feels monumental.

Katsuki flops onto his bed, grabbing the remote and tossing it at Izuku. He’s one of the only ones in the class with a TV in their room having always claimed that he didn’t like watching the shit the ‘idiots’ picked. Izuku had filed into his Kacchan notebook, right next to the older fact that the blonde secretly liked romance movies. “You pick.”

Izuku catches it (barely) and scrolls through the options, settling on something safe: an All Might movie with enough explosions to keep Katsuki entertained. They settle in, and for a while, it’s almost…normal. Katsuki mutters complaints about the unrealistic fight scenes, and Izuku chimes in with his unlimited All Might knowledge.

But then Izuku shifts closer, their knees brushing.

Katsuki freezes.

It’s subtle—a moment so brief that someone else might’ve missed it—but Izuku feels it. He feels the way Katsuki flinches, the way his leg pulls back like he’s been burned.

Izuku’s chest tightens, heat crawling up his neck. He wasn’t even trying that time, and he made Kacchan uncomfortable. This was a bad idea. “Sorry,” he mumbles, scooting away.

“What the hell are you apologizing for?” Katsuki grumbles, his eyes glued to the screen.

“I—nothing,” Izuku says quickly, but his voice wavers. He’s trying to hold it together, but the sting of rejection is sharp, and his throat tightens. “I have to go, actually.”

“What?” Katsuki sits up, glaring now. “Why?” There was something in his eyes, and Izuku could almost pretend that Kacchan didn’t want him to leave.

Almost. 

“I…well, I just remembered I have tons of homework to catch up on, so—”

“We did the homework yesterday,” Katsuki interrupts, “ Together .”

“Ah, right,” Izuku’s eyes widen as his excuse goes up in flames. “Well, I also remembered Shouto needs me to…uhm…help him clean…his room? Yes—clean his room, so I should just—”

“Izuku,” Katsuki grits. He’s getting annoyed. And Izuku’s heart is sinking further and further. “Don’t fucking lie to me.”

“I just…” Izuku starts, then stops having no other excuse.

“Spit it out!” Katsuki snaps and Izuku just. He doesn’t know what comes over him.

“Because!” Izuku bursts out, standing abruptly. His hands are fists at his sides, and his eyes are bright with unshed tears. “You don’t want me here!”

Katsuki’s brows furrow, the annoyance immediately melting off his face to give way to his genuine confusion. “What the hell are you talking about?”

“You—you flinched!” Izuku yells, his voice cracking. “You flinched like I disgust you! And you never touch me, Kacchan. You touch everyone else, but not me. Why? Why won’t you touch me?”

The words are out before he can stop them, and now he’s mortified. Why can’t the earth ever swallow him whole when he needs it to? His face burns, and he turns to leave, muttering, “I—I’m sorry, just forget it—”

But Kacchan grabs his wrist, stopping him in his tracks. The touch burns, and Izuku couldn’t pull away if he tried.

“Oi,” Katsuki says, his voice quieter now but no less firm. “Don’t go.”

“You don’t have to pretend to want me around, Kacchan.” Izuku gives him a weak, self-deprecating smile, his vision blurry, embarrassment making it hard to think. “I’m a big boy, I can take it.”

“That’s not true,” Katsuki says sharply, his grip tightening. “I—shit, I didn’t mean to flinch, okay? It’s not because I don’t want you here.”

“Then why?” Izuku demands, his voice breaking.

Katsuki hesitates, jaw clenching. His ears are red now, and he looks away, muttering something under his breath.

“What?” Izuku sniffles.

“I said because I’m trying not to!” Katsuki barks, louder this time. “Touch you, I mean. You idiot.”

Izuku stares at him, stunned. “What…why?”

“Because I…didn’t want to make you uncomfortable,” Katsuki grits out, saying the words slowly as if he’s tasting them in his mouth. He looks both furious and mortified at the same time. “With all the shit I did to you in the past…I didn’t know if you’d want me to touch you again.”

It takes a moment for the words to sink in, and when they do, Izuku feels immense relief. Kacchan didn’t hate him! If anything, he was trying to be accommodating to Izuku, which was sweet and so being added to the board. 

“You’re such an idiot, Kacchan.” He wipes at his eyes and, despite Katsuki’s indignation at the statement, starts to smile. “I’ve already forgiven you. I told you that.”

“Yeah, but—”

“I want you to touch me.” Izuku emphasizes his point by turning fully and in a moment of bravery, shifts Kacchan’s grip on his wrist so their hands interlock. “ Please touch me more.” 

Wow. He certainly didn’t mean to say that, or well, he did, but he didn’t mean to phrase it like…like he was begging Kacchan to touch him. He sounds so needy. Crap, Izuku was blowing this already!

“I–I mean—”

“Okay,” Kacchan sounds so cool, so unbothered, except that there’s this pretty pink blush and his cheeks and his hand is kind of clammy in Izuku’s and Izuku…he could die right now happily. 

“Okay?” 

“I’ll…touch you…or whatever,” Kacchan huffs, snatching his hand back and turning away in clear embarrassment. He was so cute. He grumbles something unintelligible, but then he lets out a heavy sigh. “So…are you staying or what?”

Izuku sits back down, closer this time. “Yeah. I’m staying.”

This time, when their legs brush, Katsuki doesn’t flinch.

And so, begins phase 2 of Operation Kacchan: touch him as much as possible. 

Izuku was…more or less milking his newfound privilege to touch Kacchan whenever he pleases. 

…He was deprived okay? Sue him.

The next morning Katsuki stomps into the kitchen, hair still damp from a shower, bathed in the soft glow of the sunrise and Izuku is mesmerized. Izuku’s already there, standing at the counter with a mug of tea, and he can’t resist.

“Morning, Kacchan!” he chirps, bright and bubbly, as he reaches out to poke Kacchan’s shoulder.

Katsuki freezes, eyes darting to the offending finger like it’s a weapon. “The hell are you poking me for?”

Izuku grins, overly casual. Pokes him again. Just because he can. “Just saying hi!”

Katsuki grumbles something under his breath, but he doesn’t move away. If anything, his ears are pink again. Izuku takes this as a win.

Later, when they’re studying in the common room, Izuku decides to push a little further. He leans in close—closer than necessary—to look at Katsuki’s notes, their arms pressed together.

“You’ve got a mistake here,” Izuku says, pointing at the page.

Kacchan glares at him, but his eyes flick briefly to their arms, and the tips of his ears go red again. “I don’t make mistakes, nerd.”

“You wrote ‘combustable’ instead of ‘combustible,’” Izuku points out with a teasing smile. Delighted at the way Kacchan is avoiding eye contact with him.

Katsuki clicks his tongue, yanking the notebook away, but he doesn’t shove Izuku off. “Shut up.”

The third time happens during movie night with the whole class. Izuku finds an excuse to sit beside Katsuki on the couch, the popcorn bowl balanced on his lap. About halfway through the movie, he “accidentally” lets his head drop against Katsuki’s shoulder.

Katsuki stiffens like he’s been electrocuted. “The fuck are you doing?” he whispers, his voice low so the others won’t hear.

Izuku feigns innocence, tilting his head to look up at him, and leaning even more against the other boy’s side. “You’re comfortable.”

Katsuki stares at him, his mouth opening and closing like he’s trying to come up with a retort. Eventually, he just huffs and mutters, “Idiot.”

But he doesn’t push Izuku off.

The real breakthrough comes during a training session. They’re sparring, and Izuku’s been…strategic about initiating more contact than usual. When he trips (totally on purpose), Katsuki catches him by the arm, his hands firm and grounding.

“You good?” Katsuki asks, his voice rough but quiet.

Izuku nods, breathless. “Yeah.”

Katsuki doesn’t let go right away. His thumb brushes against the inside of Izuku’s wrist, and it feels like fire and safety all at once. Izuku looks up at him, heart hammering. He needs to calm down. Something as simple as Katsuki’s hand around his wrist shouldn’t make him feel like passing out. 

And yet.

“Thanks,” he whispers.

Katsuki grunts, his eyes flicking away as he lets go. “Don’t be so clumsy, nerd.”

But there’s a softness to his tone that makes Izuku’s chest ache.

(What the hell was that?” Kaminari asks, eyebrows furrowed in confusion at the unnecessary dramatics of the show that Katsuki and Izuku were giving them.

“Ignore them, they’re gay,” Ochako sighs, rolling her eyes and dragging him to get back to work.)

After that, it’s like something snaps in Katsuki and now he’s the one initiating too. They play footsie under the kotatsu during study sessions. Kacchan throws an arm around Izuku’s shoulder and steers him out of the classroom to have lunch together. Even when they spar and Kacchan has him pinned, he lingers for a second before letting Izuku go. Sitting on top of him, chest heaving and bangs falling into his face and just staring. The touches burn and the stares are just as bad, and he doesn’t store away that mental image for later. He doesn’t.

Scout’s honor.

By the end of the week, Izuku’s high on life, and physical touches, and interestingly enough, has a new observation to add to his collection: Katsuki is clearly struggling to keep his composure, and it only happens with Izuku. Every little touch—every bump of shoulders, every hand on his arm, every accidental brush of their fingers—has Katsuki flushing red and grumbling under his breath.

It’s adorable, really. And it’s making him jump to dangerous conclusions.

“I don’t think this is necessary,” Tenya says, eyes wide with concern. 

Izuku pauses in his attempt to draw that image of Katsuki hovering over him that has been haunting him for days onto the whiteboard. “I feel like it is.” 

“No, it’s really not,” Ochako insists, nose wrinkled in disgust. “We’ve all sparred with Bakugou before. We don’t need to see your horny fantasy, we’ve heard enough about them already.” 

“They’re–it’s not—” Izuku burns bright red, stuttering over his explanation. “It’s for science!” 

Shouto sniffs. “Anatomy?”

Izuku ignores them, and finishes his final touches on Kacchan's perfect spiky hair. It was a little wonky, but that wasn’t the important part. “There. This,” he gestures widely to the expression he drew. “Is how he looked at me. My current theory is that there’s about a 53% chance of Kacchan liking me back.”

“Oddly specific number,” Tenya comments, watching Izuku as he picks up his Kacchan notebook and flips to page 83. 

There were now five facts to be considered when running the calculations. 

1. Kacchan liked physical contact.
2. Kacchan made physical contact with their whole class on a regular basis (averaging about 5-6 touches initiated a day not including the ones where others touch him first. And no, it's not weird that Izuku counted)
3. Kacchan refused to touch or be touched by Izuku Kacchan let Izuku touch him regularly and does the same!!!!!!!!!!!
4. Kacchan gets flustered whenever he and Izuku touch, but not with anyone else.
5. Kacchan gives Izuku The Look

Izuku could be oblivious at times, but he wasn’t stupid. Kacchan only reacting in that way to Izuku meant either he really hated it, or really loved it. Izuku was desperately hoping for the second one. But either way, it meant he was in need of another experiment to find out.
When he explained all this to his friends though, they were giving him blank stares.

“I would like to point out,” Tenya says when he’s done, exasperation evident in his tone. “That you could just talk to him and the experiment would not be needed.” 

Izuku stares at Tenya like he just suggested wearing socks with sandals. “Talk to him? I’m trying to confirm his feelings, not get a concussion!”

“Are you sure you’re not trying to get your face kissed?” Ochako deadpans, crossing her arms.

“Is that an option?” Izuku asks without thinking, and when everyone groans, he clears his throat, ears turning pink. “I mean, uh—no, this is purely scientific! I’m collecting data!”

He gets three blank stares again. 

“Okay, well…maybe not all science.” Izuku mumbles, blushing. Just because the experiment…benefitted the scientist doesn’t mean there’s no validity! 

“You know what, knowing Katsuki, this might actually be the easier option,” Shouto shrugs, sipping his tea.

Izuku decides to ignore him and flips to page 84 of his notebook. “Right. So, based on the pattern of behavior—”

“The pattern is you’re obsessed,” Ochako interrupts.

“—we’re moving on to the next phase of Operation Kacchan ,” Izuku finishes, ignoring her. He erases his previous drawing of Kacchan in all his chiseled glory (privately mourning the loss) and scribbles a quick diagram on the board: a stick figure labeled Me and another labeled Kacchan , surrounded by hearts, question marks, and what looks like tiny explosions. Izuku thinks it's very accurate. “I’m calling it…The Ambush.”

Shouto tilts his head. “Sounds violent.”

“Do you need help?” Kaminari asks, poking his head in from the doorway. Why is the door open? This is private business! “Because this sounds like my kind of chaos.”

“No one is helping!” Tenya snaps, waving his arms. “Because there is no ambush! This is ridiculous—”

“It’s foolproof!” Izuku insists, pointing again at tiny Kacchan on the board, and then drawing an arrow between him and stick figure Izuku. “All I have to do is set up a situation where Kacchan has no choice but to show his true feelings!”

Ochako pinches the bridge of her nose. “Izuku. Sweetie. This is manipulation.”

“This is science ,” Izuku insists.

Shouto shrugs. “I think you should do it.”

“ What?! ” Tenya yells.

“Thank you, Shouto!” Izuku beams, clutching his notebook to his chest. At least someone believes in him.

Shouto takes another sip of tea. “If nothing else, it’ll be entertaining.”

The Ambush takes place two days later, in the kitchen. Izuku had bided his time, waiting, watching in the shadows for the perfect moment…okay, he sounds a little crazy here. But this is for the good of science! He positions himself perfectly, waiting for the exact moment when Kacchan opens the fridge door to grab more vegetables for his stew. Which smells delicious by the way. Izuku will be taking some later. 

Katsuki closes the door and Izuku is now standing there, having jumped out from behind the wall. “Kacchan!”

Katsuki jumps . “The fuck, nerd?!”

Izuku doesn’t let him recover, stepping into Katsuki’s personal space with reckless abandon. “I need your help!” he blurts out.

Katsuki frowns, his usual irritation tempered by what looks suspiciously like concern. “With what?”

Izuku hesitates for a fraction of a second. Then, with all the confidence he can muster, he grabs Katsuki’s hand, lacing their fingers together. “This!”

Kacchan’s entire face turns red. His hand is really warm and kind of sweaty and perfect. Everything about him is perfect. “Wha—”

“Is this okay?” Izuku asks, staring at him earnestly. His heart is pounding, but he keeps his grip steady. “Do you hate me touching you like this?”

Katsuki looks like his brain just short-circuited. “I—what—no—I don’t—what the hell are you—”

“Because I don’t hate it,” Izuku presses, his words tumbling out in a rush now. “I like it. I really like it. And I think—I hope—you like it too.”

For a moment, there’s nothing but the sound of their breathing and the distant shouts of their classmates. Then Katsuki growls, low and frustrated, and tugs Izuku closer by their joined hands. Except they were already close so now they’re just pressed chest to chest, holding hands. Katsuki smells like caramel and the cologne his mom got him for his birthday. Izuku thinks he might pass out.

“You’re such a dumbass,” he mutters, his voice rough but not unkind. His eyes flick away, and his ears are practically glowing. “Of course I fucking like it.”

Izuku feels like the world tilts beneath his feet. Watches the way Katsuki avoids eye contact and shakes a little bit. That 53% chance goes up to 67%. 

“I have to tell you something, Kacchan,” Izuku admits, pushing a fraction closer. Hoping Kacchan can’t feel his heart threatening to beat out of his chest. “I’ve been doing an experiment on you.” 

“Huh?!” Katsuki reels back. Izuku moves with him, refusing to let the contact go. Kacchan is wearing his ‘kiss the cook’ apron, a gag gift from Kaminari and Sero. Izuku thinks that that’s really not a bad idea. 

“An experiment,” Izuku repeats, the words falling out of his mouth. “To see how much I can touch you without you getting mad. Except I’ve been watching you, and you seem like you like it. And now the experiment’s done.”

Katsuki’s eyes are wide. He’s still blushing as he licks his lips and meets Izuku’s eyes. “And what was the result?”

“There’s, uhm,” Izuku’s mouth goes very dry. Is it getting hotter in here? “A 67% chance.”

Katsuki takes another step back so that his back hits the counter. Izuku follows, cages him in. “Chance of what?” 

Kacchan is giving him The Look again. Izuku is a scientist but well. Sometimes he has to put aside his precautions to get satisfying results. “That you like me back.”

It seems like Kacchan stops breathing for a second. Then, “Back?”

“Yeah.” 

They’re quiet, staring at each other for a long moment. Long enough that Izuku starts to regret saying anything, and starts looking around for the hole again. 

Then Katsuki gets red , so red Izuku is mildly concerned for his health. 

“Make it 100%,” he breathes into the nonexistent space between them, and then Kacchan is kissing him.

Wow. Remember when Izuku said he could die happy before? Well, he really could right now. Kacchan’s hands cradle his face like he’s something precious, and Izuku grabs onto his waist so his knees don’t actually give out on him. Izuku’s skin is on fire everywhere they touch. He wants to burn to ashes.

When they part, and Izuku’s soul re enters his body, Kacchan is smiling at him. Izuku wants to frame it. “Does that change the results of your little experiment?”

“Uhm,” Izuku licks his lips. They taste like Kacchan. “Inconclusive. I think I need a few more trials.” 

Katsuki snorts, the sound soft and full of something Izuku can only call fondness. It’s like seeing the sun shine after a storm, warm and bright and blinding. He reaches up to tug lightly on one of Izuku’s messy curls, his grin tilting into something sharper. “Nerd. Always gotta overcomplicate shit.”

Izuku laughs, breathless and giddy, and presses his forehead against Katsuki’s. “It’s called the scientific method, Kacchan. You wouldn’t understand.”

“Try me,” Katsuki fires back, his voice low and steady, but there’s a challenge in his eyes. A promise.

So Izuku kisses him again. It’s clumsy and too eager, but Kacchan leans into it, his hands sliding from Izuku’s face to his shoulders, pulling him impossibly closer. Izuku thinks this might be his favorite kind of experiment—the kind where the results are clear, tangible, and absolutely, unequivocally perfect.

Katsuki pulls back first, his breathing uneven as he glares half-heartedly at Izuku. “That conclusive enough for you?”

Izuku hums, pretending to think. “Still might need a few more data points. For accuracy.”

“You’re such a pain in the ass,” Katsuki mutters, but his lips quirk into another smile, soft and genuine. He pecks him on the lips six more times (Izuku counts). When they part, Izuku grins so wide his cheeks hurt. He’s going to write in his Kacchan notebook that his lips are soft.

“Stop being creepy, Nerd,” Kacchan says, and did Izuku say that out loud? Crap.

Katsuki chuckles, shaking his head, and pushes Izuku back just enough so that he can smooth out the rumples in his ridiculous apron. “And get outta my way. Dinner’s gonna burn if you keep hovering.”

“Oh! Right!” Izuku stumbles back, hands flailing for balance as Katsuki smirks at him. His face is still warm, his heart still racing, but he can’t stop beaming. He makes to leave the kitchen, but Kacchan stops him with a hand on his wrist. He pulls him around the island and seats him at one of the chairs at the counter. 

“I don’t trust you to do anything except entertain me,” Kacchan scoffs, but he’s blushing again. He’s asking Izuku to stay with him, in his own convoluted Kacchan way. Izuku needs this dinner to be finished so he can kiss him again. 

“Of course, Kacchan,” Izuku grins.

In his head, he finally drafts the conclusion of the experiment. 

Operation Kacchan
Analysis:

• Initial hypothesis confirmed.
• Kacchan enjoys physical affection specifically from me.
• Kacchan’s receptiveness to touch correlates strongly with proximity and emotional vulnerability.
• Post-confession results show increased physical affection initiated by Kacchan (hugging, hand-holding, kissing).

Conclusion:
The probability that Kacchan likes me is now officially 100%