52-year-old housewife Michiyo Yashiro. Lately, her husband has become suddenly busy with work and can no longer participate much in family life. While she wants to believe his explanations, deep down she feels anxious—wondering if there's something more behind his absence. Overcome by loneliness and isolation, she finds herself masturbating at home—even with her son around. Yet, she never imagined that her own son would one day take such action toward her.