Kurumi's parents had taught her that a wife's duty after marriage is to serve her husband, but Walnut was kicked out of the house due to a misunderstanding by her jealous husband. As she was standing aimlessly in a park all day in the cold, a suspicious man kindly offered her shelter. Understanding her situation, the man even offered her a spare room. Kokoro by the man's honest and kind behavior, the polar opposite of her husband, Walnut offered her body to him as a token of her gratitude, and to spite her husband, she repaid his kindness by being as unfaithful as possible.