As most students have no interest in Sumo Hinomaru decides to tempt potential members with Chankonabe, but this only attracts Chihiro Kunisaki, a mixed martial arts wrestler. While Chihiro has no interest in Sumo he and Hinomaru bond over their drive to become champions and invites Hinomaru to his exhibition fight. Reina Gojo, Yuma's sister and Student Council President, develops a grudge against Hinomaru for defeating her brother. At the exhibition Hinomaru challenges Chihiro to a match. As Chihiro does not consider Sumo a genuine martial art Hinomaru suggests Chihiro fight using wrestling rules while Hinomaru will follow Sumo rules, despite this giving Chihiro a distinct advantage...