Daichi and Chiharu's only son, Yuta, is hospitalized at a university hospital in Tokyo with an incurable disease, and surgery is extremely expensive. A wealthy man named Yanagi is willing to cover all of Yuta's surgery costs under certain conditions, so Daichi and Chiharu go to see him in person. Yanagi offers to hire Chiharu as a sex slave for one year. Daichi is strongly opposed to the idea, Chiharu Chiharu's strong desire to help Yuta gives in and he signs the slave contract.