Asahi has been playing the role of a good mother, hiding her true lewd nature in front of her son, but her true colors are revealed in a "dick guessing game." Her son and his friend line up with their faces hidden and their dicks out, and they have to guess which one is her son's. It was just a prank, but Asahi's personality changes drastically when she sees a dick, so this game causes her to go out of control...