One day, the Sumikkos find an old, patchwork-covered building at the edge of the forest. Upon entering, it appears to be a toy factory. Invited by the bear factory manager, the Sumikkos start making toys, with the skillful Shirokuma using a sewing machine, Penguin? inspecting with a magnifying glass, and so on, each utilizing their strengths in toy-making.

However, as they continue to help out, strange things begin to happen. It seems there is some secret associated with the factory......