Yuku is a young mouse who lives with her family in the cellar of a castle. Her grandmother passes on the family values by telling her timeless folk tales. Injured in a tussle with a cat, the old mouse is bedridden and she tells her children that she will have to leave them to follow the little blind mole into the Earth’s tunnels. In one of her grandmother’s storybooks, Yuku learns that the flower of the Himalayas can bring her eternal light. She leaves on a journey of discovery to find the flower.