火垂る Hotaru [Fire Flies] – Tadao Sawai (1980)
Sawai’s response to a moving short story about a young boy and his infant sister starving in an air-raid shelter after losing everything near the end of the last world war, fire flies were captured for light. After death of his sister, the boy created a funeral pyre. When the fire was just ashes, he was surrounded by many, many fire flies.
The boy was to die in the year the war ended.