Misuzu doesn't get along well with her stepfather. In order to make a living, she suppresses her complicated feelings and decides to support his remarriage... but it turns out that the reason her stepfather decided to remarry her mother was because of her stepdaughter, Misuzu's young body. And today, while her mother is out, her stepfather gives Misuzu a sex education, and the timid Misuzu is unable to refuse and ends up doing what her stepfather tells her to do...