Katsuki spots the handprint on Deku’s shoulder while they’re changing in the locker rooms. It’s faint but there is no denying that it's in the shape of a hand. He feels anger boil inside.
‘Who did this to you?’ he thinks. He walks up to Deku, who has his back towards him and lightly grazes the lifted scar tissue on his shoulder.
Deku flinches and turns around with a surprised face. “WHAA-cchan, you scared me.” Deku scratches the back of his neck and makes a flustered face. “What’s wrong Kacchan?”
“Where’d you get this scar nerd?” Katsuki says with a scowl on his face. He lightly touches the scar again, this time letting his hand linger a few seconds before retreating his hand back to his side. The words ‘who hurt you like this’ go left unsaid.
Deku is surprised by his inquiry, at first he thinks he must be joking but once he looks at Kacchans face he can instantly tell that there is no recognition, only concern, curiosity, and is that sadness in his eyes?
Deku smiles softly at Katsuki and quickly puts on his shirt. “Oh, it was an accident from a long time ago Kacchan. Are you ready to go?”
Katsuki is surprised by his nonchalant response. As if the idiot doesn’t have a fucking handprint burned onto his skin. He watches as Deku puts on his backpack and starts turning to the door.
Katsukis scowl deepens. “Haa?! It’s in the shape of a fucking hand shitty Deku, are you not gonna tell me how it happened?” He grabs his bag and walks up to Deku and slightly shoves him.
Deku sputters “O-oh um its.. I.. um..”
Katsuki growls. “Spit it out, nerd.”
Deku looks away with what looks like an ashamed face “I’m embarrassed please don’t make me say it.”
Katsuki feels his cheeks grow warm and he walks away with a simple “Oh.”
Deku chases after him with guilt on his mind for lying to him. He just can’t believe Kacchan doesn’t remember but it’s better he doesn’t know because he forgave him a long time ago.....
Katsuki lays in bed, restless. He can’t get the damn nerd out of his head. Who could’ve done that to him? A villain attack he never mentioned? Katsuki falls asleep dreaming of green hair and emerald eyes enveloped in flames.
The next day in class he watches Deku talk and laughs with that half and half bastard and he’s pissed. That damn nerd never acts as calm and relaxed with him. He watches as Todoroki sets a hand on Deku's shoulder and he feels a pang of jealousy pool in his gut.
He starts stalking towards them and then it clicks.
Katsuki rages. Mini explosions leaving his palms. He walks up to them and shoves Todoroki away hard.
“Don’t fucking touch him you half and half bastard!”
Todoroki pushes himself up from the ground but before he can do anything Deku is in front of him.
“Ka-Kacchan what are you doing?”
Katsuki lets out a growl. “He’s the one who gave you that scar isn’t he? What the fuck are you doing letting him do those things to you, you idiot?”
Deku goes from worried to surprised to angry. Katsukis surprised. This damn nerd cares so much about this idiot that he’ll defend him even after what he did?
“He didn’t do anything to me. I told you it was nothing!” Katsuki ignores him and turns to Todoroki who now just has a stupid confused look on his face.
“How fucking dare you do that to Deku? I’ll fucking kill you before you think about touching him again!” Katsuki is seething with hatred but when he turns to shove Deku out of the way he sees the way his emerald eyes glisten with unshed tears.
Katsuki stands frozen in front of him, his hand hovering between them like he’s instinctively reaching towards Izuku. He feels his heart constrict, it’s breaking, at the pained expression on Deku's face but he can’t let this go.
“There’s no fucking way you’re protecting this fucker?! I’ll kill ‘em, just fucking watch me.” Katsuki charges towards Todoroki but he halts when he hears Deku yell.
“STOP,” he screamed. “JUST STOP.” He weakly pushes Katsuki and turns to Todoroki.
“Izuku..” Katsuki says but Deku ignores him and turns to Todoroki.
“Todoroki I’m sorry but can you let me talk to him, alone?”
Todoroki visibly relaxes, he gives Deku a sad nod and walks away.
“Kacchan, please. Come with me to my room. I’ll explain.” Deku lightly wraps his hand around Kacchans fingers and tugs. His sad eyes feel like they’re stabbing straight through Katsukis heart. Katsuki hates himself more than he hates that half and half bastard at this moment for making Deku look like that.
Once they’re back in Deku's room Kacchan is sitting in his bed while he watches Deku slowly take off his shirt. Katsukis breath catches in his throat when he sees his body. He is always surprised by the scars that litter his body
Deku once again grabs Katsukis but this time he sets it in the burn scar on his shoulder “Please don’t be upset.” He says with such fondness and love in his voice Katsuki feels like he was just punched in his gut.
Katsuki looks into Deku's eyes and a memory flashed in his mind. Middle school. Smoke coming from his palm and the words ‘Take a swan dive off the roof’ and ‘Defenseless Izuku’ bounce around in his mind. Recognition flashed in his eyes and he snatches his hand away as if he’s the one who got burned.
His eyes sting with tears and if Katsuki thought Deku broke his heart before, it was nothing like what he felt now.
Tears fall down his eyes and the next thing he knows he’s sobbing, tugging at his hair. “Kacchan it's okay. It's okay, please. Kacchan look at me. Please don't cry.”
“I-I did that to you. I hurt you. I always hurt you.”
He hears a sob catch in Dekus's throat and when he looks back up at the nerd tears are streaming down his freckled cheeks.
Green eyes staring at him. They shone so brightly it hurt. Deku was staring at him with a glint in his eyes. As if Katsuki were precious. More precious than anything else in the room. As if he were everything.
Deku wiped his tears with the back of his hands, new ones instantly running down, droplets of it clinging to his green lashes and Katsuki hated himself for thinking that even when crying, Deku was the most beautiful person he had ever seen. Katsuki had made him cry so many times during their lifetime and maybe it was time he fixed this. Because even if he was pretty when he cried, there was no comparison whatsoever when he smiles.
And Katsuki thought he had put more tears in his eyes than smiles on his lips.
Katsuki pulls Deku forward to his arms, Deku now straddles his lap. Heartbroken, Katsuki gathers the smaller boy in his arms and buries his face in the crook of his neck.
“M’sorry. So fucking sorry,” he whispers, kissing bare skin. “Keep hurting you but I’m gonna do better. Gonna take care of you Izuku. Okay?”
Deku sniffles while Katsuki presses kisses onto whatever skin he can reach. It made the nerd cry harder and so Katsuki tightened his hold.
They’re laying in bed now. Deku's head in Katsukis collarbone. “..you’re really warm.”
“The hell, you cold?”
“Mmh no but this feels nice.” Deku breathes deeply and Katsuki can feel it, so intimate so close. “I’m-I’m really happy Kacchan.”
Katsuki doesn’t care how his voice sounds breathless and cracking all on its own. Not when Deku is looking at him like that, beaming at him, leaf green eyes shining and gorgeous, his lips twitching up into a gentle smile.
“Yeah.” Deku breaths back and he leans forward and presses their lips together.
It's a simple closed-mouthed kiss but it's enough for Katsuki to come undone. Unraveled. Open and bare for this one person.
He tastes like peppermint and home and so god damn sweet it aches in the furthest corners of Katsukis soul.
He’ll never get enough of him. He’ll never want to give this up. He’ll fight with fangs and claws to keep this as long as Deku allows him to.
Katsuki has never been more acutely aware of how much he doesn’t deserve Izuku than in this moment. Still, as Deku intertwines their fingers together and looks at him with eyes that shine like stars, Katsuki can’t help but want to deserve him. And if he has to spend the rest of his life to earn the right to be loved by Deku, then so be it.