For years, Reiko's husband Tatsuo had been in poor health. Despite the strain, Reiko had faithfully cared for him without complaint. One day, their daughter Asuka and her husband Hayato suggested a hot spring trip, and the couple agreed, believing it would help with Tatsuo's recovery. Arriving at a tranquil, refreshing hot spring inn, Tatsuo's smile returned day by day. Seeing her husband so happy, Reiko finally began to relax, soaking in the baths to ease her own exhaustion. But she didn't realize what was about to happen—within hours, her life would change forever.