It started as a joke.
Really, it did.
They’d been messing around during lunch, and in the middle of telling a joke, Denki had wrapped an arm around Katsuki’s neck easily.
It wasn’t anything new, this routine. Denki giving his affection, Katsuki rejecting it remorselessly.
What wasn’t routine was the miniscule flinch of Katsuki’s shoulders under Denki’s arm. And then he was snarling, shoving the latter a way a little too hard.
“Geez man, accept my love!” Denki whined loudly. The red-eyed boy just cursed at him with a hard glare.
He was grumpier than usual for the rest of the day, but Denki brushed it off as one of his many bad moods.
(That was his first mistake.)
A few days later when Hanta placed a hand at the base of the back of Katsuki’s neck absent-mindedly during class, the blonde whipped around so fast he sent his table flying, explosions already flickering to life in his palms.
“Calm down, dude, I was just passing on the homework packets,” Hanta said, eyeing the blonde’s tensed shoulders warily. Katsuki was silent a few moments, eyes scanning the classroom as if daring them to say anything. Finally, he snatched the packet from Hanta’s outstretched hand and sat back down at his seat with a scowl and his shoulders hiked to his ears. no one mentioned it, simply watching in apprehension.
But Denki’s brain was buzzing.
He mentioned it to Mina in passing during English class.
“Dude, Bakubro’s totally got a ticklish neck!” he said to her under his breath, and she turned to give him a dubious look.
“I don’t think he’s capable of having a ticklish anything, Kami.”
Their gazes both flicked over to the blonde in question, who was quietly working through his worksheet diligently like the nerd he was.
Then, slowly, Mina tore a corner off her paper and scrunched it into a ball, before tossing it at Katsuki’s back. the two watched in silence as it sailed through the air and ricocheted off the back of their target’s neck. The second the ball made impact, Katsuki’s head was shooting up and his pencil was snapped in his grip, explosions flickering in his hands again and earning a look of exasperation from Present Mic. Katsuki’s almost feral gaze caught onto the duo, and he gave them a look of pure wrath that they met with sheepish smiles.
Word spread quickly after that, and it became a small contest in the class to try and touch Katsuki’s neck to watch him squirm.
Eijirou looked uneasy at the idea of riling him up like this, and Izuku was downright annoyed at the little game, giving everyone who participated in it a disappointed frown. But everyone else continued nonetheless, even students like Ochako and Rikido getting involved.
Tsuyu would brush the back of her hand across his neck when walking past where he was seated on the common room couch, and the class would hide their snickers at the way the blonde would jerk to his feet and away from the touch, palms crackling menacingly.
Mina would wrap her arms around his neck in an impromptu piggyback in the corridors and get thrown to the floor for her efforts, grinning all the while at the reaction she garnered.
(None of them noticed the way Katsuki’s shoulders would tremble minutely even after the touches faded, or the way his eyes would grow distant and panicked. Of course they didn’t - not when he hid it behind explosions and loud cursing.)
It went on for more than a week, Katsuki growing increasingly irate and agitated with each instance. He avoided everyone more, except for Eijirou and, surprisingly, Izuku.
He would eat his meals in his room, wear his jackets with the collar popped up. At trainings, his explosions were erratic and frenzied, and in class he would snap at anyone who approached him, reverting back into his anger the way he had in their first year.
“I think you guys should stop.” Izuku had said quietly around a mouthful of pork at dinner one night. The class was seated in the common room sans Katsuki and Eijirou, who were eating in the latter’s room. “You’re getting him worked up for no reason.”
He was brushed off easily, the class laughing his suggestion away.
“Loosen up, Mido,” Kyouka grinned, bumping his shoulder lightly. “Bakugou’s just allergic to affection, we’re messing around.”
“You can consider this exposure therapy!” Mina piped up, earning another round of chuckles.
Izuku scowled into his rice. “You’re not therapists.” he muttered under his breath.
That night when Katsuki and Eijirou brought their dishes down to wash them in the kitchen, Yuuga brushed past them and trailed a finger across the side of Katsuki’s throat innocently, making him drop his plate and jerk away with a curse.
“Will you fucking- stop!” he roared, face growing red instantly and lips parting in a snarl. "Stop it! Stop fucking touching me!”
Yuuga apologized easily with glinting eyes and glid out of the kitchen, leaving Katsuki hunched over the counter with clenched, trembling fists.
After a moment of tense silence, Katsuki finally dropped his plate in the sink and stomped away, not even bothering to wash it. Eijirou followed him quietly, turning to give the sniggering occupants of the common room a glare as he passed.
“You guys are being so unmanly.” he muttered with a frown.
“What an overreaction.” he faintly heard Mineta pipe up from the couches as the door closed behind them. Eijirou's scowl deepened, fists clenching at his sides.
“Dude,” he called, speed-walking to catch up to the blonde. He raised a hand to put it on Katsuki’s shoulder but was shoved away roughly.
“Fucking leave it, Shitty-hair.” Katsuki spat, storming into his room and slamming the door shut behind him.
Eijirou was left standing in silence, staring at the closed door in frustration as he realized Katsuki had gone back to calling him that goddamn nickname after the entire year it took to finally convince him to use his name.
It came to a head two days later.
Katsuki had been studying at the common room tables while the class was out training. He’d fallen asleep at some point, head buried in the arms he had crossed over the desk.
The class started filtering in slowly at some point, eyeing his prone form slyly as they entered. Eijirou was nowhere in sight, probably still outside, and Izuku was at an internship meeting.
The one to finally make the move was Denki. He sidled up to Katsuki, inching a hand towards his unmoving form as the group watched in anticipation. Then, as quickly as possible, he wrapped his hand around the back of Katsuki’s neck, palm pressing flat against the skin, and squeezed.
It happened so fast Denki was left disoriented. One moment Katsuki was asleep and the next he was startling awake with a strangled curse, explosions crackling at his palms as he jerked away and to his feet.
“Dude, dude, it’s just me, chill!” Denki cried between snorts of laughter as he reached out placatingly, the entire class watching the scene in amusement.
But Katsuki didn’t calm down. In his half-asleep state, he lurched away from Denki’s outstretched hands with an aborted cry, sparks in his hands growing to dangerously large explosions.
“Imagine that,” Kyouka snickered into her palm. “The great and mighty Bakugou Katsuki, bested by a single touch to his neck.”
She didn’t see Katsuki’s flinch at the words, the way his face twisted and his shoulders began to tremble.
Spitting out another string of weak curses, Katsuki turned away from them and towards the dorm rooms only to be stopped by a bewildered Eijirou, who had just entered.
“What’s going on?” he asked hesitantly, eyeing his snickering classmates and then Katsuki, who was trembling in his grip with a lowered head.
“Fucking let me go, please, just stop,” the blonde whispered hoarsely, quietly enough that only Eijirou heard it.
The redhead recoiled at the words, almost losing his hold on the blonde’s arm.
“What the hell is going on?” he demanded again, at the group this time.
The class were still chortling slightly, unable to see Katsuki’s expression from where he was turned away and assuming his shaking was in rage. The blonde's expression was twisted, entire body tensed tightly and fists curled and trembling at his sides.
“You think this is how the villains got him?” Mineta leered. “Just a hand at his neck? Must’ve been easy as hell!”
Eijirou felt the flinch that ran through Katsuki’s body at the words, and the blonde’s head dipped even lower, hair falling over his face. His breathing was shallow, chest starting to heave slightly.
“Hey-“ Eijirou began, nervousness edging into his body at the way Katsuki's breaths were coming out in short puffs, but Shouto was already cutting him off with a frown.
“That’s too far, Mineta.” he said quietly, looking irritated. A few of the students nodded in agreement, suddenly looking less amused after the purple boy’s comment.
“I’m just messing around!” Mineta shot back.
“Well don’t mess around about tha-”
A choked sob cut through the argument, and they all froze, heads swiveling to the source.
“Bakugou?” Eijirou asked quietly. The blonde’s body was trembling visibly at this point, shoulders shaking and hand pressed to his mouth tightly. A droplet of moisture fell from his bowed head and onto the floor, and Eijirou blanched.
“Shit- dude. Bakugou.” he reached for the blonde’s shoulder only for him to flinch away from the touch violently, uncontrolled explosions roaring at his palms. Another sob tore itself from the blonde’s throat, echoing through the silent common room.
“What’s going on?” Mina asked quietly, looking completely terrified.
“Someone get Aizawa-sensei.” Eijirou whispered. “I don’t- I don’t know-”
Tenya ran off in search of their teacher instantly, and Eijirou turned to the hunched over blonde, gently ushering him away from the centre of the room and towards a corner.
“Bakugou,” he tried slowly, an edge of panic seeping into his own voice at the sight of his best friend’s tear-stained and rapidly reddening face. “Katsuki. You need to breathe.”
The blonde shook his head, expression twisting desperately. “C-can’t,” he choked out, hand creeping up to clutch the back of his own neck. “Can’t, I can’t!”
Tears were falling freely at this point, staining Katsuki’s shirt quickly.
“No, they’re- I can’t, please-” Katsuki gasped, grip tightening at his neck until the skin went white. His expression had twisted into one of pure terror, eyes glossing over.
Eijirou’s own eyes were starting to well with tears at his helplessness when Aizawa-sensei came skidding into the common room.
“What happened.” he asked briskly, maneuvering Eijirou away from Katsuki smoothly.
“I- I don’t know, he just started-” Eijirou tried numbly. “I don’t know.”
Aizawa-sensei pulled Katsuki out of the common room and into the corridor, and the class was left standing in tense silence.
“I told you guys to stop!” Eijirou cried finally, voice shrill as tears finally rolled down his own cheeks. “I told you!”
His classmates flinched, all of them pale and shaken.
No one spoke.
They waited, unmoving until Aizawa-sensei was walking back in, a still-trembling but slightly better-looking Katsuki trailing behind him with swollen eyes trained on the floor.
“Someone better explain to me what the hell happened.” their teacher said finally, murder in his eyes.
Mina was the one to do it, shakily explaining with stilted pauses how the game had started.
Aizawa-sensei listened quietly, expression growing stonier with every passing word. When the pink-skinned girl finally finished with tears welling in her eyes, he fixed them all with a stare angrier than the one they had received after Kamino.
“Do you all know what that was?” he asked lowly. “Harassment. You harassed your classmate.”
Another flinch ran through the group at the word.
“Sensei, we didn’t mean to-” Denki began quietly, but he was stopped by their teacher’s raised hand.
“I don’t care what you meant. I’m telling you what it was. You harassed your classmate and led him to a panic attack. You’ve all been through enough together to understand the trauma that can follow your experiences as heroes, so why did none of you have the common sense to stop and consider why Bakugou didn’t want you touching his neck?”
Silence followed his words for a long moment, before realization dawned on the class as one.
“Oh my god,” Ochako whispered in horror, eyes filling with tears. Denki and Mina went very still next to her, stilling as their own eyes widened in guilt. The blood drained from Kyouka's face, and she suddenly looked very ill. The atmosphere in the room grew heavy, and their gazes slowly trailed to the blonde sitting hunched at Eijirou’s side, still trembling minutely.
“I think you all owe Bakugou an apology.” their teacher said finally. “Every single one of you except Kirishima and Midoriya will be attending after school detention every day for a week.”
For the first time ever, there were no protests. Aizawa-sensei pushed to his feet, and with a lingering glare at the group of them, brushed out of the common room.
When the door shut behind him, they sat in tense silence.
“Bakugou,” Eijirou whispered hoarsely to the unmoving blonde at his side. “Can I-”
His arm reached out, making an aborted movement to hug the blonde before he paused mid-way. But a moment later, Katsuki leaned forward to bury his face in the redhead’s shoulder and nodded weakly in consent. Eijirou’s arm settled around him slowly, resting at his hip and avoiding his neck area clearly.
“B-Bakugou?” Denki started shakily. “I fucked up really bad. I’m sorry.”
Katsuki shrugged weakly against Eijirou’s chest.
“’s fuckin’ whatever.” he mumbled roughly, looking uncomfortable with all the guilty looks being directed at him.
“No!” Mina cried. “It’s not whatever! We were horrible to you even though you kept telling us to stop!”
“I’m sorry, too,” Ochako echoed quietly. “It was easy to forget how traumatic Kamino would have been. You’re so strong that I forgot you were a person like us, and I never thought about how you would have been affected by it.”
There were murmurs of agreement throughout the group as they all gave their apologies to the awkwardly fidgeting blonde.
“This is fucking stupid.” he muttered finally, flushing slightly. “Can we just pretend it didn’t happen?”
They all chuckled lightly.
“It’s nothing to be embarrassed about!” Mina insisted. “If I was in your position I probably would’ve cried the entire time the villains had me!”
“Honestly, I think they’d just return you at that point, Ashido.” Hanta mused, earning another round of laughter.
“Well maybe that was my escape plan the whole time!” she cried dramatically. “We can’t all be inhumanly strong and powerful like our Bakugou over here!”
She kicked at his side lightly amidst the class’ laughter, eyeing him cautiously as if checking if the touch was allowed.
Katsuki just nodded at her once, making her beam as her shoulders sagged in relief.
“Shut up, dumbass.” he rasped, but there was a smile tugging at his lips.
From his side, Eijirou watched the exchange with a faint grin of his own.
(Later, Izuku would return from his internship and receive a rundown on what happened. The class would cower as they received a stern tirade from the green-haired boy that put Aizawa-sensei’s lecture to shame, while Katsuki sat behind him and watched the entire thing smugly.)