The story follows two brothers, Junpei and Kanta, who live on the island of Shikotan, weeks before the end of World War II, on August 15, 1945, Soviet soldiers land on Shikotan and occupy the island. Junpei and Kanta, who live with their grandfather, a fisherman, and their father, the head of the firefighting force of the village, are forced to move to the stables while the Russian commander's family, among them the commander's daughter Tanya, move into the main house. At school, Russian children occupy half the building, and Tanya and the other Russian kids begin to mingle with the Japanese children at recess. After a playground jostle makes Junpei bump into Tanya, they become friends and the two brothers are subsequently invited to Tanya's house for dinner.