With his wife close to giving birth, her mother Tina comes to the city to help. His wife’s burden eases, but he is desperate after being forbidden to masturbate for a month. Though he knows it is wrong, he cannot stop staring at Tina’s voluptuous body. He then peeks at her naked in the bath, only for her to catch him and say, “Ren, I know you’re watching.” The discovery opens the door to repeated breeding sex between son-in-law and mother-in-law.