He can't say exactly when he met Midoriya Izuku. He was just always there from his earliest memory to their third year of middle school.
They used to be close once, there was a time when Katsuki honestly enjoyed the time he spent with Izuku most. They both loved heroes and All Might was their all time top favorite. How could he not be he was cool, brave, strong and he always won every fight.
That's where he got his drive from, like All Might he would always win, always be on top, always be the best.
He was the best too, he had the best quirk, the best grades, everyone sung his praises and told him he was the greatest.
Izuku was the first one to call him the best. He was the first one to tell him he could do it. He was the one who always followed him around and hung on to his every word. Even though he was quirkless.
He remembers thinking when he first heard the news that Izuku was useless. He remembers the big smile on izuku's face even though he was two seconds away from crying.
God he was always so easy to cry. Even over the smallest things like when he got extra pork in his katsudon, when he passed a test, when he watched an All might movie, when he was happy, sad, angry, scared those tears never seemed too far away.
But that day when he looked at Katsuki declaring he'd be the greatest hero ever without a quirk, even though he was hurting, he had never seemed so bright. It was the first time Katsuki disliked him. The time when Katsuki fell in the river and was trying to act tough even though it hurt. That time while his 'friends' laughed at him it was Izuku who rushed to help him hand out concern in his big green eyes. It was then that Katsuki felt humiliated by him, he was angry that the quirkless cry baby had been the one to help him with out a second thought. It was the First time Katsuki thought he was looking down on him.
When Katsuki and his friends were being little shits and beating up that dumb kid in the sand box because Katsuki thought he was weak it was Izuku who rushed to help. Like a real hero, protecting the weak and innocent from villains. It was the first time Izuku stood up to him and told him he was wrong. He didn't like that...he hated it. He felt small and ashamed because he was right. It was the first time Katsuki hated him.
He hated that even though Izuku was outnumbered and didn't stand a chance he still decided to fight. Even though he was left on the playground bruised, singed and beaten while Katsuki and the others got away without getting in trouble. Even though Katsuki won he felt like he lost and it made him angry.
He called him useless, he had everyone calling him useless since they were 4 years old. He chased him away when he followed him because the sight of him just made him so angry because he refused to give up on his pipe dream. Didn't the idiot get it?! The strong will always win and come out on top. He was the best, he always won and Deku would always be nothing but a loser who was beneath him if he couldn't learn his place.
He thought he'd be free of him when he went to U.A, he had gotten the highest score, he had been training for years to always be in top condition. He had worked hard to improve his quirk and it was finally paying off. They were piling on the normal praises because of course he deserved them he always did, but then he heard Deku passed as well. He felt as if time slowly ground to a halt. He looked at the scrawny, trembling sorry excuse of a wimp babbling on trying to defend himself from jeers and taunts. He passed the written test. He actually thought he could just waltz into the UA entrance exam, going up against people with all sorts of quirks, going up against Katsuki himself who had been working his ass off for this, and just win?!
He saw red. He had never been more insulted in his life, this useless fucking twerp thought he could just waltz in and ace it? This shitstain who has never trained a day in his goddamn life to even put on an ounce of muscle and only stalked and fanboyed over heroes and write in his shitty notebook thought he could just do it?! He really must think Katsuki was some fourth rate trash he could just look down on. He was going to put him in his place once and for all and make him see reason.
He remembers when he grabbed him and slammed his frail still aching body against the wall. He remembers him flinching body still sore from when Katsuki had beaten him up two days before. He made him bleed that time and had burnt him too, he remembers now the bandages peeking from under his shirt and the healing burn marks. He remembers them now but back then he didn't care how much he hurt him as long as he got his point across and kept him beneath his boot.
He set off his explosions right next to his face and he remembers the sadistic satisfaction he felt watching him flinch and reel from the force of his explosion. He remembers faintly smelling something burning but he didn't care to check, he probably gave him a serious burn with that one.
He remembers the fearful green eyes staring back at him as he demanded he drop out and forget about U.A. He remembered telling him how a useless nobody like him couldn't possibly get in and he must think that UA was some kind of joke. He remembers him desperately mumbling something about not being allowed to use his quirk at school and he sent off another blast in his face. He'd relished the pain filled cry he got from him as he cowered against the wall. Thinking he'd finally gotten through to him then those same terrified green eyes glared back at him fiercely filled with tears and a storm of emotions saying he would still do the exam and spouting crap about there not being a rule against quirkless students. He hated that look most, because that look made him think he just might do it. He just might make it into UA and become the best and go on to be the next number one hero quirkless and all. While Katsuki would be beaten and forgotten just some other second best.
His body sung with white hot rage as he grabbed that stupid precious notebook of his and blew it up in his palms and threw it out the Window. His words dripped from his lips in arrogant venom as he walked towards the exit.
"You wanna be a hero so bad? I've got a time saving idea for you. If you think you'll have a quirk in your next life...go take a swan dive off the roof!!"
Izuku was looking distraught at his precious notebook in the pond when he turned and glared at Katsuki in a way no one has ever looked at him before. It was anger, hurt,anguish, frustration and hate. Katsuki's response had been automatic he set off a few threatening explosions and glared with equal hate and disgust at the boy daring him to make a move. He didn't and Katsuki had left feeling triumphant as he remember the look of defeat as the fight bled out of Izuku and something seemed to have withered a bit in those green eyes.
Katsuki left feeling rather good about himself but with a sinking feeling in his gut he ignored.
Looking back at it taking on the sludge villain by himself back then had been an incredibly stupid idea that almost killed him. He knows he was a little shit and disgustingly full of himself back then but he would've given Sparky a run for his money with how fucking idiotic he was being. If seasoned pro heroes couldn't handle it then who the hell was he to try. He knows why he did it but he still cringes to himself when he thinks about it .
He remembered thinking he was gonna die, just like that while a disgusting parasitic pile of questionable sludge suffocated him and stole his body. His batshit old hag was gonna kill him. He remembers feeling absolutely terrified as his vision started fading while the heroes looked on trying to contain the chaos. Then just when he thought that was it, he had a moment to gasp precious air. He thought he was saved when he saw the last person he expected to rush in and help him. It was Izuku, small and determined and quaking as he clawed at the sludge trying to free him. When he asked him 'Why?' he remembers that shaky smile as Izuku told him he looked like he needed help.
He's not too sure what happened after that, his mind had been focused on Izuku, the next moment he could only describe as being hit with hurricane force winds then falling on his face in the dirty street gasping for air.
They had told him he was brave and heroic for trying to take down the villain while they scolded Izuku for being reckless and stupid for rushing in and that he should've let the heroes handle it. The same heroes who were just about to cut their losses and make him die if one sorry little wimp hadn't tried to save him. Ultimately it was All Might that saved him and despite the praises he felt angry and disgusted with himself.
Because he wasn't the hero in all this...it was Izuku.
He had debated with himself on whether or not he should say something to Izuku but his pride had ultimately gotten the better of him and he refused to thank him at all. He didn't know that would be the last time he saw Izuku. Not until weeks passed and he never showed up for school. He thought he must've been sick and it's not like anyone else noticed of cared anyway. But this was that over zealous little fuck wad who didn't miss school for anything.
It wasn't until he was walking by the staff opened door of the staff room and overheard the teachers whispering about it.
"Such a bright kid"
"I know such a shame but he was quirkless so it must've been hard"
"His mom found the note before he could actually do anything though"
"Hey you don't think they'll start blaming us teachers do you?"
"Hey don't say stuff like that he didn't even die. He was just a wimpy little kid who couldn't take the real world and tried the easy way out. Besides he's left remember"
"Oh yeah where did he go again?"
"Who cares I say good riddance to Midoriya Izuku he was always a problem child"
If you asked him what happened after that he honestly couldn't tell you, he was in a daze. Izuku had left? When? Where did he go? Why the fuck did he leave?
The next thing he knew it was late afternoon and he was standing at the gate of the apartment complex Izuku and his mother lived. He didn't know why he was there, he had a feeling there was more to the story than he knew but did he have a right to ask?
Note? Was it a suicide note?
The very thought still made his stomach twist with dread. It was his fault.
No it wasn't his fault, that stupid nerd was a coward who wanted the easy way out. He couldn't take it like the teacher had said. Katsuki didn't do anything wrong.
Those were the words he told himself till he got home. Those were the words he made himself believe and that the fucking nerd would finally stop making a fool of himself and accept reality.
Right Katsuki didn't do anything wrong.
But all these years later he knew he was dead wrong. He just didn't know how wrong he was and would be in for a ride.
He wants to be forgiven.
Forgiveness is wasted on guys like him.