The scene is Hiroshima. In the early summer, the boy looks up to heaven. In the boy's mind was a girl who took her own life, a poet with a sense of guilt, and a dead man. The poet's heartbreaking cry echoes in the boy's chest. The boy heads to the riverbank with a female student who knocked on the door of the boy's heart. The boys see the transparent river flowing red. Director Otomo, who has produced works with the motif of the atomic bomb, has worked on the theme of the atomic bomb three times, "Illusions to Encounters" and "Let's play tomorrow".