Kenichi, who has been bullied but wishes to be strong, joins Karate club upon entering senior high school. However, he gets picked on by the other pupils in the club everyday. One day, Kenichi meets Miu, a beautiful girl who has just transferred from another high school. On Miu's suggestion, Kenichi decides to be a disciple of Ryozanpaku, a mysterious training establishment. Kenichi could not imagine the brutal training he receives from the martial arts masters there... However, now Kenichi is marked by Ragnarok, a street gang group, and he is constantly defending himself from them.