A family gathers together for a commemorative ritual whose nature only gradually becomes clear.
The hyperactive teenage scuba diver, Hikari Kohinata, lives in a small town near the sea. On her first day of high school she meets the shy transfer student, Futaba Oki, who is struggling to find a place after moving away from Tokyo. Hikari takes the lead, dragging Futaba into her hijinx, and the two soon become close friends
Ryota, a timid salaryman who has difficulties fitting in at home and work has his average life changed after his estranged father falls ill. Along with his wife Sae and their only child Moe, he travels to his father's country town, where he begins to uncover his father's mysterious past spent searching for a mythical creature.
