The Haruna family, consisting of a wife, her husband, and her father-in-law, live together harmoniously. However, they are troubled by their inability to have children, so the wife consults her father-in-law. Although the father-in-law is also at a loss, the wife thinks that since her husband has many brothers, perhaps her father-in-law's sperm is very potent. She ends up asking him for artificial insemination. What started as a business-like arrangement gradually turns into an obsession with sex for the wife. They agree to end their relationship once she gets pregnant, and when pregnancy is confirmed, their relationship comes to an end. However, after giving birth, they can no longer hold back and resume artificial insemination…
