Fire Woman Matoigumi

The hero comes to Shirosagi High School as a first, second, or third-year exchange student and on his first day sees a bully picking on a girl. When he tries to help, he is beaten and saved by a trio of girls from the school's Matoi-gumi club. They are all really good at martial arts and he decides to join their club with the intent of winning their hearts by saving people in trouble.