Troubled by a lack of intimacy with his wife, Yuma visits a call girl service to relieve his frustration. There, he is met by none other than his mom friend, Reina. He tries to leave in a panic, but she, with a professional demeanor, smiles gently and says, "I've already received payment," inviting him in. From that day on, Yuma becomes addicted to the forbidden pleasure he experiences with his mom friend, a forbidden act...