In 1945, American troops land on the island of Okinawa. Facing a guerrilla war against the invaders, young Ryuko is forced to leave her grandparents behind and flee with her mother and younger sister, who are later killed. Alone, Ryuko traverses the war‑torn island and eventually finds refuge in caves occupied by Japanese forces, where she witnesses Japanese soldiers committing suicide with hand grenades. The story is adapted from a children’s book written by Akira Aratagawa and Hikuji Norima, which itself was inspired by real American footage of an Okinawan girl, Tomiko Higa, waving a white flag at the island’s surrender.