As Izuku got kicked from his own squad due to his now ex friends being jackasses to him the Bauksquad plus his Girlfriend Momo noticed that and took him in and seems to love him being around them since they really consider him one of the strongest  since he was able to save them even Katsuki. With Katsuki after Izuku saved him from the sludge as the pros tried to nag him on being a hero he told the pros of it wasn't for Izuku he would've died which made people question about what they did and Katsuki turns around and apologizes to Izuku about bullying him and on how he regrets on doing it as Izuku forgave him and they became bros.  Katsuki deeply respects Izuku after that but he does keep his energy like before but more chilled a little to the point of you bother him where he doesn't like being bothered he will yell.

Ship

Katsuki x Camie

Izuku x Momo

Mina x Kirishima

Jirou x Denki

The rest of the class respects Izuku it's just that his old squad doesn't due to thinking they are the shit when they had Izuku with them.