This role-play is performed by adults. My younger sister, Mei, was distressed by the sounds of porn coming from her brother's room. One day, Mei reunites with her childhood friend Mamoru. Mamoru is drawn to Mei's mature appearance. The distance between the two of them suddenly narrows when they hear the sound of a porn production coming from their brother's room next door. Frustrated by the sound of her brother watching porn, Mei feels intensely having sex for the first time with her childhood friend...