In the summer of 1958, a riverside village is regularly threatened by typhoons. There, a boy named Yucha learns the local flood legend from a Kami-Shibai (paper theater) storyteller. He tells of a broken-hearted girl who drowned herself in a river pool deep in the mountains. It is said that her grief has caused great floods every few decades ever since. A great typhoon is approaching. Yucha sets off for the pool deep in the mountains, which even adults fear, in the hope of stopping the flood.