Tomoya gets into a fight with his friend Kenji, who came over to play, and after winning, he handcuffs Kenji, leaving him unable to move, and goes off to play somewhere. When Tomoya's mother comes home a while later, she tries to remove the handcuffs by looking for the key, but finds that it is tied to Kenji's penis. Kenji is in a hurry to get to cram school, so she has no choice but to try to get the key, but as she watches the pre-cum dripping from Kenji's erect penis, which is stimulated by her hand, her mother begins to feel strange...