While her husband is away on a work assignment, mother Yuko is temporarily living with her daughter and son-in-law. Though she feels lonely, she realizes she's not the only one—she notices her son-in-law Tohru frequently masturbating alone late at night, and can't help but feel it's more than just someone else's problem. She isn't the only one suffering from loneliness. Gradually, Yuko becomes increasingly aware of her own unsatisfied desires, blaming her daughter for the emptiness. But before long, she starts craving Tohru's huge cock, and begins seducing him nonstop, 24/7. Yuko's heart shifts from seeking relief from solitude to actively pursuing her son-in-law.