After her husband's business fails and their finances collapse, Hana Aoyama, wife of the Aoyama family, reluctantly turns to her father-in-law, Ginji, for help. Eventually, she begins living with him, avoiding total ruin. However, taking advantage of the eldest son's absence, Ginji starts seducing Hana at night. Already burdened with loneliness, Hana consciously uses her body to satisfy her father-in-law's desires. As a result, their relationship grows deeper, leading to new and escalating complications.