Japan, 1945. Every day, American planes drop bombs from the sky and set whole swathes of land on fire. In the inferno of such an attack, fourteen-year-old Seita and four-year-old Setsuko lose their mother. Without their father, who is in the navy, the children are left to fend for themselves. Their aunt does not welcome the extra hungry mouths in the prevailing famine. So the siblings move into an abandoned bunker and try to survive there on their own.