Hisako loses her home in Tokyo to Allied bombing. With her husband fighting somewhere in Asia, she and her two children evacuate to a suburb of Kobe, where they share a house with Hisako's cousin, Kyoko. Kobe is bombed and Kyoko is killed. Hisako is forced to take care of Kyoko's two children in addition to her own, but there is not enough food for everyone.
In the final months of World War II, 14-year-old Seita and his sister Setsuko are orphaned when their mother is killed during an air raid in Kobe, Japan. After a falling out with their aunt, they move into an abandoned bomb shelter. With no surviving relatives and their emergency rations depleted, Seita and Setsuko struggle to survive.