A young oni child lives with his father in a remote mountain dwelling, isolated from human settlements. His father gives him a red handball obtained near the home of a human girl named Yuki. This gift deeply troubles the child, prompting an ethical decision to return the item to its owner. The next morning, he journeys through the snow to a human village. He observes children playing together before finding a small house where Yuki sits alone. He silently returns the ball. Yuki states her name, thanks him, and reveals the ball's sentimental value as something made by her sick mother, easing his concern. Returning the ball sparks a connection between them, planting the seeds of friendship. This encounter forms his core documented story, marking a shift from isolation to building an inter-species bond through an act of restitution.