Nana lives with her mother and leads a married life at her parents' home. Recently, she has been having a lot of days where she and her husband, who is always busy with work and neglects the family, pass each other by. One day, her sister, Keiko, comes home with her husband, Toru. After dinner, Nana and Toru find themselves alone and Nana ends up complaining about her husband. However, Toru is also troubled by his cold relationship... As they share their common worries, the distance between them gets closer, and the two of them, who are in an unacceptable relationship, can't suppress their desires and end up indulging in a double affair.
