Omusubi Kororin

Omusubi Kororin is a short animated film produced by Gakken, a Japanese publishing and educational media company known for its commitment to children's literature and traditional folklore. Released as part of a series intended to preserve classic Japanese nursery tales for a modern audience, the film adapts the popular fable of an honest old man who discovers a hidden world of mice inside a hollow stump after his rice ball rolls away.

The production reflects the mid-century Japanese animation style common to educational filmstrips and short-form storytelling of the era. By focusing on moral clarity and rhythmic, repetitive storytelling, Gakken aimed to provide culturally resonant content for classroom and home viewing. While it is less widely cited than the major theatrical works of the time, the film remains a noted example of how animation was utilized in Japan to bridge the gap between historical oral traditions and emerging visual media.