Mai, a masochistic student, is discovered by her sadistic teacher, Uni Shiokawa, and lured into a secret sexual club. Mai confesses that her poor academic performance stems from uncontrollable fantasies of being taken by men. Shiokawa understands her desires completely and invites her to a hidden gathering of extreme S&M activities behind the school. Delighted by her first ever training session, Mai's excitement pleases Shiokawa. Their masochistic chemistry is perfect, driving their games deeper and deeper. As their mutual cravings intensify, they push each other toward ever-greater pleasure.