To save her son's life, who suffers from a serious illness, Hibiki, the wife of Hitoshi, makes a contract to become the sexual servant of a wealthy man named Hosokawa for one year. Hitoshi laments his own powerlessness for having to sell his beloved wife, even if it's for the sake of their son. Videos sent weekly by Hosokawa record Hibiki's training process from beginning to end, and although Hibiki initially shows a strong attitude, she gradually becomes entirely subservient to Hosokawa...