After losing her husband, Ryouko was forced to live with her daughter and son-in-law. Though her life appeared peaceful, her desires grew stronger each day, and masturbation became a regular part of her routine. As her craving for intense pleasure deepened, her longing gradually shifted toward wanting intimacy with someone. The forbidden relationship with her son-in-law began when he accidentally discovered her masturbating. Struck by her eroticism, he started pursuing her. Though Ryouko resisted out of guilt toward her daughter, she couldn't ignore the heat rising in her body, overwhelmed by uncontrollable lust.