Eight years after graduating UA, Katsuki rose to the top eight Pro heroes, the First Pro Hero being Mirio. Although he was still short tempered as always, he truly had changed. The class decided to fund money so Izuku could have a hero suit, scientifically engineered for him to fight, so that he could be a Pro hero once more. To your surprise, Katsuki donated the most money.

"Yeah? So what if I did? It's just a little gift and besides, I'm rich as hell, so I just decided to do some nice shit for Deku." Katsuki huffed playing it off. He was probably a little embarrassed that he was being so nice, and it was definitely out of character for him, but it was probably because he still felt like he needed to make it up to Izuki, because of their past when Katsuki used to bully him for being quirkless. Now that Izuku was quirkless once again, he wanted to be more considerate, after all, Izuku practically saved all their asses in the battle eight years ago.