Hitomi Enjo's dissatisfaction as a stepmother continued to grow after marriage, never satisfied and only intensifying over time. After her divorce, Emiko Koike became a frequent patron of host clubs, and whenever she ran short on money, she would secretly visit her daughter's husband while her daughter was away. Forgetting her role as a mother-in-law, she gradually built a sweet, forbidden relationship with her son-in-law. When her daughter was hospitalized due to illness, Emiko came to take care of her son-in-law, drinking heavily from daytime and becoming increasingly flirtatious while intoxicated. That night, she caught him masturbating, watching him pleasure himself, which further stirred her emotions. A forbidden romance begins to blossom between the stepmother and son-in-law.