The youngest boy had two older sisters: the eldest, Mai, was always kind, and the second, Tsubasa, had a bit of an S&M streak. When the eldest sister returns home after a month, the brother is delighted. One day, the brother, having failed at chores, suddenly becomes Tsubasa's obedient slave. Upon learning this, the eldest sister, in an attempt to counsel him, ends up engaging in sex? In the end, he is brought to ecstasy by the combined chastisement of both sisters, subjected to a double penis punishment.
