"Charm Point 1: Sister’s Rondo" is a 1999 one‑episode hentai OVA that follows two sisters at the same college—one working as a young teacher and the other as a student—who each date men their own age and face opposite sexual problems in their relationships. The story contrasts the younger sister’s frustrated lover, who can’t satisfy her, with the older sister’s situation of having a partner who’s overly eager, leading to erotic complications and comedy-drama between the four characters.