Koji Tsukino returns to his old high school as its new math teacher. From his long hair to his cold, aggressive nature, Koji looks nothing like your usual teacher and everything like the former delinquent he was. Assigned as his supervisor is Mr. Nitta, who used to teach his math supplementary lessons. Koji may pretend to be indifferent towards him, but don't get him wrong - he only became a teacher because of Mr. Nitta! If that's the case, then why won't he just say so?