Ai, who works at the same convenience store as her boyfriend, has only ever known one man. Until now, she has never questioned his roughness in bed, but gradually begins to feel an uneasy sense of discomfort due to the lack of intimacy. One day, she accidentally sees the store manager's enormous erection. Driven by a strong curiosity about large genitalia and an insatiable sexual desire, she begins to innocently assault him, a married man.
