Reiko married into the founding family of a large company and lives a wealthy life. However, her husband is always working and doesn't care about his family, and recently his sexual desire has dried up... Unlike her husband, she has always been Kokoro to her Kokoro -hearted son, Kosuke. Reiko is troubled by her secret love for her son, but her curse is lifted by a letter. The letter says that Kosuke was switched at birth. Kosuke is saddened by this fact. However, he secretly sees Reiko as a woman, and he can't help but press his lips together in a hot, wet kiss...