English is not my first language. My apologies for any mistakes.
...But this is what you wanted.
Every story that starts with 'Once upon a time' is expected to have a happy ending despite how it began.
Once upon a time, there was a princess waiting to be rescued from the castle she was trapped.
Once upon a time, there was a prince who wanted to get married out of love.
Once upon a time, a brave hero raises victorious after a disaster strikes.
Once upon a time, he was a total jerk with all the people around him. Being classmates, teachers, elders, his family, his parents, his 'friends'...
To him.
Once upon a time...
Once upon this time, he told his childhood friend to jump out of a rooftop.
And he listened to him.
As you can start to imagine, this story doesn't have a happy ending at all. In fact, Katsuki knows that his story hasn't even started yet, and he already screw it up.
Because once upon a time, a couple of hours later after he just told his childhood friend to jump out of their middle school rooftop to see if he can get a quirk in his next life, he found him.
Midoriya Izuku.
Fourteen years old.
Cause of death: suicide.
But Katsuki knows better, and he knows the real cause of the death of Midoriya Izuku.
It wasn't the loss of blood after the falling, it wasn't the hit his head made against the pavement, it wasn't the fact that one of his lungs fell after the impact nor his broken ribs or all the fractures he got.
No.
He knows better.
Midoriya Izuku.
Fourteen years old, about to turn fifteen in a few months.
Cause of death: him.
Him, who bullied Izuku until (literally) his death. Him, who couldn't keep his mouth shut for once in his life, who even his 'bully friends' told him that maybe he went too far this time.
It's terrible, isn't?
Well, it's even worse living it.
He doesn't have peace with himself anymore. There isn't a moment where he can't help but feel guilty for what happened to Izuku. Every day at every hour he's always thinking about that night, about how he would give anything to just go back to that day to stop himself for saying those awful words to Izuku.
The only time where he's at peace it's when he's about to wake up. Those precious seconds where his brain hasn't woke up yet, those wonderful seconds where he's at peace and doesn't know anything and... And then, everything starts over again.
But he's just a kid, fucking hell that he's just an idiot kid. A stupid kid who told his childhood friend to kill himself without thinking the actual meaning of those words.
"Bakugou"
He looked up an saw Kirishima's brilliant smile, his eyes wide open with excitement that they were almost sparkling.
Oh, Jesus. He can't take that smile.
"Yes?" he said quietly.
"Dude, your quirk is amazing!" Kirishima said while he passes one of his arms around him "I mean, you can make explosions! That's sooo mainly!"
Your quirk is amazing!
"Yeah, it's pretty cool" another smiling boy joins them. Kaminari? Yeah, he thinks that's him "I wish my quirk was as amazing as yours"
I can't wait to have a quirk of my own! I hope is as amazing as yours!
Some other students also get close to them and Katsuki is starting to feel the pressure.
Shit. Shit. Shit.
Is this what people call a panic attack? Because he's panicking at the moment and he's thinking about that night. He's always thinking about that night.
"One would have expected from you to have an explosive personality as your quirk," a girl with pink skin said "But you are pretty chill"
Y' already made him cry... stop it! I won't let you!
Katsuki hits with both of his fist his desk and everyone jumped in surprise. So far, this boy hasn't spoken with anyone unless it's really necessary, like answering Aizawa-sensei during the test of their quirks.
In the meantime, Katsuki is struggling not to tremble.
Holy shit.
This is getting worst.
The bell rang and then he took his backpack and got out of the classroom, ignoring his classmate's calls.
Oh God, this is torture.
Why is everyone so nice? He was expecting a bunch of teenagers full of themselves, like his old self and not caring about anyone besides their goal: being the best hero in the world.
But no, everyone acted so nice and kind. They...
They would have perfectly got along with Izuku.
He blinked confusedly when he looked at the door and then realized where he was. Is it always going to be like this? Getting lost in his own thoughts while his body moved without him even realizing where?
He sat in front of the door and let out a deep sigh.
A part of his mind was telling him to go away while the other part of him is telling him that he should stay even when he knows that he shouldn't be here and that nothing good will come out.
Shit.
Shit, shit, shit and more shit.
He's only fifteen years old and he's so tired already.
"Katsuki"
He looked up and saw green hair along with green eyes. So sad and tired eyes. He stood up immediately and took a few steps back, getting away from the door.
"What are you doing here?" Midoriya Inko asked with no emotion at all.
She got thin again, like when he was in kindergarten. But he knows it's not because she decided to eat better or eat less.
It's because she probably stopped eating at all.
"You should go home," she said after taking a deep breath and not giving him a chance to speak at all, "I think I made myself clear with you and your mother that I don't want to see you again"
The once kind Midoriya Izuku was gone. There's only left one really sad lady that's only living because she has to.
And again, it's all because of him.
She opens the door of her apartment and when she was about to close it, Katsuki finally speak.
"Today was the first day"
And that's all he needed to say to stop Inko of closing the door. However, she wasn't looking at him.
"I..." Katsuki swallows hard "U.A. is..."
Amazing.
Annoying.
Everything I imagine.
Full of cheerful people.
Izuku would have loved it.
"I'm going to be a hero" he declared, making himself to believe it too.
Inko turned around and Katsuki saw the most hateful glare on the women that he took a step back by instinct.
"You better"
And she closed the door.
Half an hour later, he's already at his house.
"I'm home," he said quietly.
He hears rushed steps, quick and desperate whispers and then loud sound of a door lashing.
He let out another sigh and took out his shoes.
He walked into the living room and saw his father sitting on the couch reading the newspaper.
"Ah, Katsuki" his father smiled at him forcefully "Welcome home"
Katsuki only nodded.
"How was your first day at U.A.?"
Amazing.
Annoying.
Full of cheerful people.
I don't deserve to be there.
"It was good"
His father nodded at him and then he got up and left the newspaper at the table that was in front of the couch.
"Your mother left you some dinner"
Katsuki opened his eyes with surprise and rushed to the kitchen. In the middle of the dining table was a single plate full of rice and only one tiny trout.
The dish was so sad, but Katsuki's heart jumped full of feelings and felt like he was about to cry.
"It's a start," Masaru said behind him "But at least she's making you food again"
"Why?" he asked, "Why are you not...?"
He swallowed hard, unable to finish that sentence.
"Why I'm not behaving like her?" his father let out another heavy sigh before he continues "She may be hotheaded, but your mother is actually very fragile. You broke her heart, Katsuki. And it wouldn't be fair for you nor her for me to take sides"
His father put a hand on his shoulder and Katsuki almost flinched at the contact.
"Good night, son"
His father left him alone in the kitchen. He supposed he opened the door of their bedroom because he was able to hear some sobs.
"Oh, Mitsuki" he heard his father voice.
And then, it was absolute silence.
Katsuki took the dish, removed the plastic from it and put it on the microwave.
He knows he didn't break his mother heard.
He broke her.
Since that day, his mother hasn't spoken to him, she hasn't looked at him, she stopped making him food, washing his clothes, cleaning his room, giving him some money...
She was pretending Katsuki wasn't around, as if he didn't exist.
As if he was the one who died.
The food was ready and now he was sitting at the dining table alone. He looked at his food and then at the two empty chairs in front of him. What was before an annoying dinner with his noisy parents, the two of them laughing and talking to no end and bothering him with a bunch of stupid questions while they ate an almost buffet, now it ended with him eating completely alone. At least this time he didn't have to cook.
"Itadakimasu"