The older sister, an elite career woman is actually a serious brocon. When she goes to clean her younger brother's apartment, who's in university and started living alone, she finds an an*l porn video. After watching the DVD, the older sister becomes interested in an*l sex and begins to an*lly masturbate right then. When her younger brother Takashi comes home then, he sees a bizarre scene, but his crotch swells at the sight of his older sister's ass sticking out, so he forgets himself and plunges into her an*s with great force. The older sister becomes Takashi's meat toilet for the sole purpose of pleasure.