Chiharu and Kazuaki come to visit their friend Natsuo's house. Unfortunately, Natsuo is not there, and only his recently divorced sister Minako is there. Seeing Minako masturbating out of loneliness, Chiharu is unable to suppress her desire and approaches her. Although she is confused, her desire explodes at the sight of a man she has not seen in a long time, and she begins to hungrily suck on his cock. What will Kazuaki do when he hears about it later?!