For 16 years, Chisato has lived the daily life of a housewife, sending off her husband and son at the front door and tending to household chores. Once called "Chisato" by her husband, she gradually became known as "Mom" or "Kaa-san," and as her name changed, so too did her sense of self as a woman—slowly fading away. Within the peaceful rhythm of family life, she was beginning to forget her own femininity. Then one day, she meets a painter whose presence awakens long-dormant desires and sensuality within her. During an intensely thrilling afternoon encounter, she is enveloped in pleasures she's never known before, crossing the line a married woman should never cross. This is the story of a bound housewife who steps beyond the boundaries of ordinary life and discovers a new version of herself.