It’s the late summer of 1958. A boy named Yucha lives in a riverside village that is constantly threatened by typhoons. He learns the local flood legend, which has long been passed down through the community, from a Kami-Shibai (paper theater) storyteller. Showing an illustrated paper card for each scene of the story, the storyteller tells of a broken-hearted girl who drowned herself in a river pool deep in the mountains. It is said that her grief has been causing great floods every few decades ever since. A great typhoon is approaching. With childlike curiosity, Yucha sets off for the pool deep in the mountains, which even adults fear, in the hope of stopping the flood and soothing the girl’s sorrow.