Noa and Nobuo who had been married for three years and lived a happy couple life. One day, he brings Kuroda at his home. Her husband, Nobuo, then often invites Kuroda into the house. Noa gradually loses her heart to the younger, more tolerant Kuroda than her husband, and eventually gets a relationship. But there was an unexpected fact. In order to improve couple's life of a mannerized night.