The Morizawa family, consisting of a wife, husband, and father-in-law, live together harmoniously. However, they are troubled by the lack of children. The wife consulted her father-in-law, but he also couldn't find an answer. Thinking that her husband's many brothers might indicate strong sperm from her father-in-law, the wife asks him for insemination. What started as a business-like arrangement gradually turns into an obsession with sex with her father-in-law. They agreed to end the relationship once she got pregnant, and when pregnancy was confirmed, their relationship ended. But after giving birth, they couldn't hold back any longer and resumed insemination intercourse…
