Kitsune

Folklore gives the fox a tail roughly every century and full power at nine. The old ones shapeshift, most often into a woman, and the stories that follow split into two piles. In one the fox marries a man, keeps house, raises a child and leaves the moment somebody notices the tail. In the other it plays tricks, lights false fires on a hillside and walks travellers into a river.

Foxes also work for Inari, the deity of rice, business and grain, which is why Inari shrines put a pair of stone foxes at the gate instead of the usual lion dogs. They often hold a key or a jewel in the mouth. Fushimi Inari in Kyoto, the shrine with the long tunnels of orange gates, is the head of a network of thousands.

The two jobs sit awkwardly together and Japanese storytelling has never bothered to resolve it, so the fox arrives either as a messenger of a god or as a con artist, sometimes in the same episode. Anime leans on the second. Fox ears, a fox mask at a summer festival, and a character who answers a direct question with a smile all point at the same source.