Medical scientist Gen Suzuki (Masato Sakai) makes a remarkable discovery in the field of cloning. His boss Michitaka Sakakibara (Masato Ibu) opposes his breakthrough due to ethical issues. They have a conflict and Gen Suzuki is soon kicked out of the research room at a university.

7 years later, Gen Suzuki learns that Megumi Tashiro's (Ayumi Ito) body was found. Gen Suzuki hired a private detective to locate her. Megumi has a 6-year-old son named Shinji (Rai Takahashi). Megumi Tashiro has not contacted her younger sister Natsumi (Machiko Ono) in nearly 10 years. Meanwhile, younger sister Natsumi begins to live with her nephew Shinji, but she doesn't get used to living with a child and her financial situation is poor. Natsumi leaves Shinji with Gen Suzuki, whom she met at the hospital. At the hopsital, Gen Suzuki told Natsumi that he is Shinji's father.

Natsumi though, feels uncomfortable with Gen Suzuki's obssession with Shinji. She decides to go with them. Meanwhile, Detective Tadashi Kuroiwa (Katsumi Takahashi) suspects that Megumi was murdered and he watches Gen Suzuki. During his investigation, Detective Tadashi Kuroiwa meets Gen Suzuki's former boss Michitaka Sakakibara. Michitaka is shocked when learning of Shinji's existence. He believes Shinji might be a human clone made through Gen Suzuki's cloning technology.