daisy's Questions (1)

I read a manga but I forgot the name mangas. İts about a highschool boy bullied by his classmates but after 20 years he came back his old higj school as a teacher but now the one whos bulliying him has a daughter in this highschool. His daughter being bullied by her classmates and she Gates her father because he is very popular. So whats going to do that boy is he protect her or he turn a blind her so I am currious but I cant find it help me please