Rei, a teacher who cares about her students, is the school's slightly airheaded Madonna, who forgets to put on her bra and unconsciously presses her breasts against the students. Yuta, a student who is approaching a sensitive age, is unable to concentrate on his studies because of Rei, and his grades have been dropping steadily. Rei, worried about this, makes a naughty proposal to Yuta, who comes to her for extra lessons one day...