After the death of her husband, Keiko (Sayoko Machimura) marries Masahiko through an arranged match. The two live together as a harmonious couple, but Shunichi, Masahiko's son whom he raised alone, feels slightly uneasy about the presence of a new mother figure. One day, Koike, an insurance agent who had helped Keiko after her husband's passing, suddenly appears at her doorstep. He invades the couple's private love nest, forcibly molesting Keiko's body and shattering their happiness. Shunichi accidentally witnesses the scene, confronting firsthand the chain of misfortune brought forth by familial bonds.