In Mitono, a remote mountain village, every child must undergo a mysterious ritual known as Warawa-Tomurai. Sixth-graders Yuuma and Honoka take part in the ceremony just before the village begins to disperse. Yuuma's family moves to the city; Honoka remains behind. Separated, the two begin to uncover the secrets behind the ritual. Within the sanctum where something inhuman resides, the children are drawn in — toward a painful fate.