Sayo has left her job as a teacher to become a married woman, while Yoshino has graduated and is working as a successful trading company employee. Although the two were once teacher and student, they made a one-time mistake. Then, 12 years later, the two meet again on the night of their class reunion. Sayo cannot hide her shock, and memories of the past inevitably come back to her, and she begins to think of Yoshino, who has grown into a strong man, as a member of the opposite sex. From then on, they once again build a twisted relationship, not as teacher and student, but as a married woman and a young man...