On a typical morning, Mio goes to wake up her son, who is attending cram school. There, she sees her son masturbating. Mio is surprised at the size of her son's penis, which she hasn't seen in a long time. Her son is embarrassed, but he feels like a woman in his mother. That night, her son peeks at Mio and his father's nighttime activities. The next morning, Mio goes into the room to wake her son. Her son makes up his mind and attacks Mio. Mio ends up accepting it. From that day on, her son continues to seek his mother's body when his father isn't looking...