In order to save the life of his son who is suffering from a serious illness, Shingo's wife, Riho, makes a contract to become a sex slave for a wealthy man named Yoshimoto for one year. Even though it is for his son's sake, Shingo laments his own helplessness in having sold his beloved wife. Every week, Yoshimoto sends him a video that records the entire process of Riho being trained, and although Riho initially shows a strong attitude, Kokoro gradually becomes Yoshimoto's...