It follows the traditional fairy-tale arc of young Budori Gusuko (voiced by Shun Oguri), an anthropomorphic cat living in 1920s Ihatov forests, whose family faces famine from sudden cold weather and disasters; he loses his parents and sister Neri (Shioli Kutsuna), wanders, joins volcano scientists to engineer an eruption for warming, and ultimately sacrifices himself. The story centers on family loyalty, personal sacrifice, and era-appropriate scientific efforts against natural disasters, remaining a faithful adaptation of the source novel with no alterations to established characters or setting. The anthropomorphic cat design stems directly from Hiroshi Masumura's manga adaptation as a stylistic universalizing choice, consistent with the director's prior Miyazawa film Night on the Galactic Railroad, not any contemporary identity framing. The production features an all-Japanese voice cast and crew with zero evidence of DEI mandates, gender or race swaps, or activist messaging in plot, dialogue, or creator statements, resulting in a straightforward children's tale free of ideological overlays.