Nanami lives with her mother and lives as a married couple at her parents' house. Lately, she's been having a hard time with her husband, who neglects her family because of her job. Her older sister Keiko returns to her hometown with her husband and girlfriend Toru. After dinner, she is unexpectedly alone with Toru, and Nanami ends up complaining about her husband. The distance that approaches by having common troubles, the two people in an unforgivable relationship can not suppress their desires and drown in double affairs.
