Married slave market

Reiko has divorced her husband and lives with her son, Hiroshi. One day, when mother and child still had the habit of taking a bath together, Reiko couldn't hide her confusion when Hiroshi told her, ``Recently, my penis gets bigger when I take a bath with my mother...'' A few days later. Hiroshi is shown an erotic video by a friend who came to stay at his house and learns that men and women have sex. That night, Hiroshi and Reiko, unable to sleep, head to the bathroom alone to relieve their fatigue...