Yuna married Madonna, a renowned novelist much older than her, and now lives with him and his son, Takashi, in a grand mansion. Their daily life is peaceful, and the family bond grows ever stronger. However, due to the pressure of his work and the effects of aging, intimacy with her husband gradually fades. One night, when Yuna accidentally touches Takashi's strong, mature body, long-suppressed emotions awaken within her. Trembling with arousal, she embraces the heat building inside her and indulges in masturbation. By chance, Takashi witnesses the entire scene. From that night on, her heart is thrown into turmoil. Torn between her dignity as a married woman and the forbidden desires stirring within, her inner conflict unfolds through intimate confessions. This marks the end of her relationship with her husband—and the shocking beginning of an incestuous affair.