Katsuta Kadomatsu, a first-year high school student who transferred to a private Buka Boys' High School surrounded by four girls' high schools just because he wanted to have a girlfriend. However, the class he entered was a group of problem children, Class 1 G, who were isolated from the school building and feared by the teachers. Katsuta is surprised by the dilapidated classroom and his classmates with strong quirks, but he spends his days happily in love and friendship. However, the evil organization Tennokai, which was supposed to have been crushed by the urban legend of the delinquent group G-Men after a deadly battle, was closing in on them.