The, also pronounced kanko, is a type of spirit possession in legends around various parts of Japan. It may be known otherwise as osaki especially in the Kantō region, and also considered equivalent to the izuna.
It was believed to assume the guise of a small mammal and able to fit inside a pipe or bamboo tube, but normally only its keeper or user (kitsune-tsukai) was able to see it. The user, through the power of the kuda, was believed capable of divulging a person's past or foretelling his future; this soothsayer was also capable of performing curses, bringing calamity upon targets. In regions where the superstition was held, a prospering household could be accused of achieving its prosperity because it was a house possessed by the spirit (kuda-tsuki). The fox (and its analogues by other names) was said to multiply in number each time a marriage took place, following the bride to her place of marriage, thus disseminating into more households.
The, which in Chinese fashion (onyomi) can also be read as kanko (old romanization kwanko), derives its name from being small enough to fit inside a tube, according to one explanation. It may also have earned its name due to its tail resembling a tube spliced in two. Folklorist Yanagita Kunio conjectured that the kuda alluded to a god's descent (verb: kudaru) from the mountain, this god Ta-no-Kami ("rice paddy god") being roughly equated with the Yama-no-Kami or "mountain god".
The is a kindred sort of spirit, employed by the "fox-user" or, (although in modern standard Japanese, the word is pronounced īzuna and denotes the least weasel).
The osaki fox is also identified as an equivalent spirit employed by the "fox-user" (kitsune tsukai).
According to one summarization, the term is prevalent in the Central region (Chūbu region), whereas the appellation izuna tends to be used in north-central Nagano and the northeast (Tōhoku), and osaki in the northern Kantō region.
The kuda-gitsune lore has traditionally been found in Shinano Province (present-day Nagano Prefecture, in the northern Central Region) and has been associated with the, the deity of Mount Iizuna in the area of Togakushi or the Iizuna or Izuna ritual (practiced in shugendō) based on its worship (cf. §Izuna below).
The kuda-gitsune also occurred in the folk-belief of more southerly portions of the Central Region known as the Tōkai subregion, namely Mikawa (in present-day Aichi) and Tōtomi Provinces (present-day Shizuoka Prefecture). It also forms part of the folklore in the southern Kantō region, Tōhoku region, and elsewhere. There are no legends of kuda-gitsune in Kantō besides the Chiba Prefecture and Kanagawa Prefecture, and this is said to be because Kantō is the domain of the osaki fox tradition.
Despite the localizations above, the ability of using the kanko/kudagitsune is purportedly obtained by trained yamabushi (the ascetics of shugendō) at their holiest sites, either Mount Kinpu or Mount Ōmine (in present-day Nara Prefecture), according to who wrote the essay Zen'an zuihitsu.
According to some sources the kuda-gitsune ("pipe fox" or "tube fox") is kept inside a bamboo tube, especially by the yamabushi. The fox in the bamboo tube may be summoned by reciting a magical incantation, and be made to answer any questions asked. Alternatively it is said that fox user (kitsune-tsukai) keeps the tamed kuda fox spirit in the bosom of his garment ("pocket") or up his sleeve, and the creature collects assorted information which it whispers to its master's ear, so that the practitioner of the art may then reveal another's history, or predict another's future. The spirit remains invisible, and can be only seen by the user.
As for its size, the Edo Period essay collection (1841) by Matsura Seizan has an entry on the kuda-gitsune, including an illustration (above) of the fox said to have been brought from a bucolic area in Osaka and exhibited in Edo in the year Bunsei 5 (1822), reporting the full length of the specimen (excluding the tail) at 1.2shaku1.3shaku. Yanagita Kunio was of the opinion however that this size represented the largest of this kind, as smaller ones were about the size of a polecat (itachi, <30 cm?).
Other sources have described the smallness of the kuda-gitsune by comparing it to the size of a house mouse, or the size of a matchbox.
The (1850) also provided visual illustration of a specific anecdotal example, which reportedly had a catlike face, otter-like body, gray-colored fur, and was about the size of a squirrel, with a thick tail.
And according to 's essay collection (pub. 1850), the kanko/kuda-gitsune is about the size of a weasel (itachi) with vertical eyes, but otherwise the same as a feral rat (or perhaps rather the yako), except its thick fur is not all matted/dissheveled.
An izuna is a fox servant, employed by certain "sorcerers" called izuna-tsukai (izuna users) in the Shinano Region (Nagano Prefecture); these familiars may also be employed by other psychic type religious or spiritual professionals in Niigata Prefecture and other parts of the Northeast, as well as in the Chūbu region, and those who profess to have special powers claim to perform clairvoyancy with the use of the izuna. The sorcerer was also believed capable of harming his client's enemies using the izuna, causing them to become possessed or to fall ill.
The izuna is considered by some believers to be a servant of the deity called the or Īzuna gongen, typically represented as a tengu standing on a white fox. Therefore, the sorcerer (izuna-tsukai) sometimes may be a worshipper of this particular gongen deity, however, that is not always the case.
Sometimes it is told to be a type of (possession by a kitsune "fox") and depending on the region, a household that has a kuda-gitsune occupying it are labeled as "kuda-mochi" ("kuda"-haver), "kuda-ya" ("kuda"-proprietor), "kuda-tsukai" ("kuda"-user), etc., and become stigmatized.
Such a family, though they main amass wealth is seen to have achieved it by striking fear among others by its fox-using, and marriage with a fox-user household was shunned by the rest. The kuda-gitsune were allegedly commanded by its master to raid other families' homes and steal their possessions, and in this way the master's family grows wealthy―or at least in the beginning. Since the kuda-gitsune multiplies until their number grows to 75, the large pack of foxes eat away at the family's wealth, bringing about their downfall.
As for the foxes quickly multiplying to 75, it is also said that every time a bride from a kuda or osaki-haunted household goes off to be married, she is said to bring 75 of the kuda minions along with her into the new household. This piece of folklore was perhaps invented as a convenient explanation as to why so many families came to be accused of being fox-owners, as time went by.
The kuda-tsuki is spiritual possession much like the hebi-tsuki (serpent-possession), inugami-tsuki (hound deity), or even tanuki-tsuki (racoon dog) of other communities, and ultimately derive from serpent-god worship, according to geography and history scholar Shōjirō Kobayashi.