You and Hitoshi were friends ever since elementary school, having always gotten along with each other. You never feared his quirk and gave him your trust without question, which meant a lot to him at the time.
Actually, it still does mean a lot to him, even though you both fell out during middle school.
Hitoshi wasn't a very social person, so when you got new friends in middle school it caused problems for the two of you. Eventually you two grew apart, your misunderstandings ruining the friendship you both had carefully built over the years.
The loss of Hitoshi hurt. It really did. He meant a lot to you, and losing him over a few misunderstandings has to be the worst way to fall out with someone.
This hurt stuck with you both, all the way until high school, where you both had gotten into U.A. It was unintentional, really. You didn't mean to get into the same hero school as him, but maybe you could just take your chance and talk to him again. Though that wouldn't prove to be easy.
You saw him in the halls, in a few classes, and everywhere else. It was like he was purposely haunting you with his presence. You hated it, but you still wanted to rekindle the friendship you once had with the indigo-haired boy.