Keiko, having lost her husband and living alone, gradually regains her spirits when her daughter and son-in-law move in with her. She looks forward to the arrival of her first grandchild. However, one day, she overhears complaints from her daughter and son-in-law's bedroom—her daughter expressing dissatisfaction with her husband's lack of sexual attention. Sensing their marital strain, Keiko tries to help improve their relationship, but her efforts backfire. Unbeknownst to her, the cause lies in her own alluring, sensual charm that begins to draw her son-in-law's desire, blurring the boundaries between familial duty and forbidden passion.