He wouldn't have watched the girl run off, a look of joy on his face with beautiful, freckled cheeks tainted a rosy pink.
He wouldn't have come running to Katsuki after school, gushing about it on their way home. He wanted to scream in that moment, to yell, to cry, to hit that idiot nerd in the face.
Katsuki had felt defeated.
He hated that his random girl that he didn't even know had wormed her way to Izuku. How could he not have seen it coming?
Didn't Izuku remember the promise they made months ago? Doesn't Izuku want to marry Katsuki?
He couldn't help it. He yelled and walked off, leaving Izuku standing there confused and slightly hurt. He remembers going into his room and just sitting there, thinking for a while.
Even if Izuku had forgotten, that didn't matter. Katsuki would make him remember. He would get on one knee and remind him.
But in that moment, one major problem remained.
That annoying girl.
Katsuki had felt very proud, because in that moment he realized something.
If Izuku never got the chance to be with anyone in a serious way, then he would most definitely turn to Katsuki, the person he had the closest relationship to.
Then, Katsuki would get his happy ending, and in turn, Izuku would get his.
—
He still remembers the crunch of her bone under his boot. This new mission to keep his promise had led to him experiencing a handful of new things.
He would have to thank Izuku someday.
She had screamed a lot when he broke her leg, who wouldn't? The good thing was, the rag in her mouth and being so far out in the woods helped with keeping the screams go unnoticed.
He had convinced her to sneak out of her room at night, only to knock her out the first chance he got and take her here.
It was kind of pitiful how easily she followed him. All he had said was that he was Izuku's best friend, and that he wanted to tell her something he found out concerning Izuku's feelings towards her.
Being that trusting had led her to a broken leg, multiple burn marks, and then being thrown into a river.
Katsuki had heard her annoying screams the whole time, that high pitched, whiny noise that made his eardrums feel like they were bleeding.
Katsuki had thought about how one day, he would tell Izuku about this moment, and he would laugh alongside him.
He would thank him and apologize, say that he felt bad that Katsuki had to hear that annoying girl's voice for more than a second.
It would all be worth it.
—
The police investigation was closed down after a month or two.
As if to prove how worthless the annoying girl was, Izuku had grieved for only a handful of days. He hadn't really known her all that well besides the confession.
Katsuki had been glad.
He wouldn't know what he would do if he had seen Izuku crying over that girl when the feeling of her bones snapping was still fresh in his mind.
Instead, Izuku had clung to him more than normal, and the best thing had been that the topic between them had nothing to do with that girl at any moment.
Weeks passed in peace, just Katsuki and Izuku, Izuku and Katsuki.
That is how it would be for the rest of their lives, Katsuki doing whatever he needed to do, and Izuku being oblivious to it all.
Katsuki will watch as Izuku's feelings for him grow and grow, until the moment comes that they become bound together forever.
He would keep his promise.
