Even at the peak of World War II, the small island north of Hokkaido, home to brothers Junpei and Kanta Senou, remains virtually unaffected. They pass their days collecting eggs and picturing themselves as Giovanni and Campanella, the protagonists of Night on the Galactic Railroad, their favorite book. However, the war soon concludes, and Soviet forces arrive to occupy the island. As their circumstances grow increasingly precarious, the two brothers forge an unlikely connection with Tanya, the daughter of a Soviet officer. Nevertheless, it may be too late for their lives to return to the carefree state they once knew.