Kobe, Japan. Jun, Akari, Sakurako and Fumi truly believe that they can confide in each other. But one day, at a party, Jun confesses that she is seeking a divorce from her husband and this information seems to upset the other three. They follow her trial as she attempts to win her case against her husband's will. To make up with each other and dispel any bitter feelings, the group then leaves on a trip to the Arima hot spring resort where Jun vanishes... This disappearance starts a chain of unexpected events in the remaining women's lives.