East Asian tradition makes the fox stranger and more numinous. The huli jing of China, the kitsune of Japan and the kumiho of Korea are fox spirits that gain tails and power with age, a nine-tailed fox is ancient and formidable, and can take human, usually female, form to seduce, deceive or occasionally to love and protect. In Japan the fox is also the messenger of Inari, the kami of rice, prosperity and commerce, and paired stone foxes guard the entrances of thousands of Inari shrines, often with a key or a jewel in the mouth. The Japanese fox is thus doubly coded: a potentially dangerous shape-shifter of folklore and, at the shrine, a benevolent servant of a major deity.
The belief that a fox spirit could possess a human being, kitsunetsuki, was taken seriously enough in Japan to become a documented category in early Japanese psychiatry, where physicians in the late nineteenth and early twentieth centuries recorded and treated patients presenting with symptoms attributed to fox possession, a genuine case of folk belief shaping the recognised medical categories of its time before Western psychiatric diagnosis replaced it. The shape-shifting fox of East Asian folklore should not be confused with a different Japanese trickster, the tanuki, or raccoon dog, Nyctereutes procyonoides, a biologically distinct canid with its own extensive shape-shifting lore; Western retellings sometimes blur the two animals together, though within Japanese tradition the fox spirit and the tanuki are kept clearly apart.