Junko walks alone along the seaside of Izu. Three years ago, she and Hiroaki were mother and son who shared a physical relationship. Every year, they enjoyed a private hot spring trip to Izu, just the two of them. On that day, after finishing their usual getaway, Hiroaki suddenly collapsed on the way home and passed away. His final words were, "I wonder if I can come see this sea again next year?" Holding those words close, Junko resolved to live on—for both herself and Hiroaki.