The firefly is a multivalent symbol in Takahata’s film, signifying the firebombs which rained down on Japan’s cities, the siblings’ joy and hope for survival, the transitory nature of young Setsuko’s life, and the regeneration of life through nature untouched by war. But in Seita’s imagination, shaped by nationalist propaganda, they are grotesque symbols of military might. Ideology has entrenched itself so deeply in Seita's psyche that he no longer sees the fireflies as a natural wonder, as Setsuko does, but as a symbol for Japan's military victory over its enemies.