After marriage, Nana is forced to live with her husband Koichi's parents. However, her main concern is her domineering father-in-law. At first, life proceeds normally, but gradually the father-in-law's attitude turns cold, and he begins scolding Nana over trivial matters. Her husband gently supports Nana's feelings, sharing warm moments with her in the living room—but the father-in-law witnesses this intimacy. The next day, he locks Nana in the basement, hurling insults and declaring, "I'll discipline this shameless wife myself," marking the beginning of a new battle.