A debt-ridden man is recruited by a Yakuza associate to become a "sex trainer" for an exclusive club that tailors women to the specific desires of wealthy clients. Under the guidance of the commanding Sakura Matsunai, he begins training a desperate young woman named Sana to help her settle her family's debts. After discovering Sana's potential and learning the ropes from Sakura, the trainer commits to the job to clear his own financial burdens.
While Shari is trained to embody a sadistic persona for a demanding client, Natsumi is lured into the industry after a staged arrest. Upon discovering that her sister, Sana, is already working to pay off their father's massive debts, Natsumi is manipulated by the trainer into joining her. Driven by family loyalty and her own emerging desires, Natsumi ultimately agrees to undergo training alongside Sana to satisfy a client's specific fantasy of having two sisters.