Returning home to visit her parents after paying respects at the family grave, Mao Hamasaki unexpectedly reunites with her former teacher from school days. Their long-overdue conversation flows naturally, leading them to continue drinking at a bar. Carried away by the mood, they end up spending the night together. The teacher has a passion for tight bondage, and Mao discovers unexpected pleasure in this new experience—one so intense she can't forget it. She begins tying herself up and masturbating, yet still feels unsatisfied. While her husband is away on a business trip, she sneaks off on a secret getaway with her teacher. Over the course of two days and one night, the intense training continues.