On his arrival at the academy ahead of the new term, staff member Joutarou quickly uncovers a concealed side to the conduct of students Mitsuki and Minami. He also learns of the striking academic gains achieved by Mahiru, younger sister of the classics instructor Hinako, and begins to suspect discreet arrangements behind those results. Recognizing his role in maintaining order, Joutarou sets out to steer the rule-breaking pupils toward proper conduct.
