The secret affair of the brother-in-law and the lewd sister-in-law. Kenji and Yuka have been married for 3 months, but Kenji cannot spend much time with Yuka. When Kenji found out he had just divorced and had no place to stay, he decided to bring her home to find a place to live. Yuka did not want to, but Kenji convinced her because he loved his brother. Initially, Yuka was very annoyed by her husband's weak personality, but gradually she realized that they were completely related and then they became closer. Since she felt very lonely after the divorce, the brother-in-law took Yuka in when her husband was not home. But gradually she realized that only her husband could bring her ultimate happiness, which her husband was unable to provide...