After her husband went on a solo assignment, Momoko lived a lonely life. Her daughter and son-in-law temporarily returned to her. At first, her son-in-law, Kunihiro, was reserved, but Momoko spent lively and enjoyable days with him. One day, when Kunihiro fell ill and she took care of him, he was touched by her kindness. From that time on, he began to see her as a woman, and eventually, they entered into a forbidden relationship. Living under the same roof, the sense of immorality gradually turned into pleasure...