My older sister Harumi and Miyuki gather at their parents' house to celebrate the 3rd anniversary of their mother's death. Her husband came later and Miyuki was growing her wings at home alone. Harumi's husband, Ippei, was staring at Miyuki with guilty eyes. The panty line that stands out from the skirt, the defenseless figure after taking a bath... And Ippei, who can no longer control his reason, devours the sleeping Miyuki. After that, Miyuki's body gradually feels pleasure to Ippei, who repeats obscene acts even when his husband joins and the family gathers.
