Ishikura is a Priest's son who has recently started working as a substitute teacher at a local high school. He finds out that Sakashita Subaru, a freshman, hates him for apparently no reason! Subaru, member of the Calligraphy Club, seems unable to forgive Sensei's indecent attitude towards women (and men). He keeps saying things like: "Don't flirt, don't be lewd", but, in spite of it all, Ishikura starts feeling drawn by Subaru's tenderness. This is the hysteric love story between a Sensei and a spoiled tsundere student.