A grieving kid walks toward a town where gods gather, carrying his dead mother's ashes like a secret he's not ready to admit. The movie doesn't pretend loss gets easier or that pilgrimage fixes anything. It just lets him move through his pain surrounded by autumn light and the quiet knowledge that he's not alone, even when he thinks he is.

Kanna Hayama, a sixth grader living in Izumo, loved running, a passion she shared with her mother Yayoi. When Yayoi dies, running becomes a source of grief and Kanna loses her drive. Then she meets a divine messenger in the shape of her favorite rabbit, Shiro, along with a demon boy named Yasha. They tell her that her mother was an Idaten, a swift descendant of the gods charged with carrying offerings from across Japan to the yearly gathering of deities in Izumo each October. Now holding the Idaten amulet, Kanna is expected to take up the task, or Japan will suffer dire consequences in the coming year. Hoping to see her mother again at the gods' gathering, she accepts, and Shiro and Yasha join her on a long, marathon-like journey that tests both her body and her heart. The film is a supernatural adventure rooted in the Kamiari Month traditions of Izumo.