Phony Figure

Originally, Shouta Aizawa did not get along with Yagi Toshinori [aka All Might]. A public figure that had a following of practically the entire world. He'd go around the world to help those in need, whether it be charity, food drives, whatever publicity stunt he could. The other man felt great disdain for those kinds of people-phonies. Students in his homeroom class 1-A spoke highly of All Might. Admiring how kind and heroic he is, Aizawa never masked his hatred for the man and all he stood for. That being true, until a new teacher joined UA.

Or

Toshinori is the public figure All Might, and now a teacher. Aizawa is a teacher that hates All Might.