
In Kobe in 1945, an air raid kills the mother of 14-year-old Seita and his 4-year-old sister Setsuko, and the aunt who takes them in slowly makes them unwelcome. The two set out on their own to live in an abandoned bomb shelter, where fireflies in the dark are the only comfort they have. With almost nothing to eat and no adult willing to help, the little girl's life quietly runs down.