An oft-cited hypothesis attributed to
Kunio Yanagita is that the
kappa is a debased end-product of what used to be a venerated water deity (
suijin). Using this hypothesis as a linchpin,
Eiichirō Ishida's sought to establish that the
kappas horse-tugging nature had its roots in some sort of cattle or horse sacrifice ritual to the water deities. But as attestation of such was wanting in Japan, he expanded his search to the Eurasian continent. Noting that in China there was an ancient practice of submerging cattle or horse as offering to the "Lord of Rivers" (
Hebo, ), Ishida conjectured that
kappa may be traced back to an importation of lore from China. Regardless of whether the Japanese veneration of the water deity owes its origin to China, there are enshrinements, festivals, or rituals associated with the
kappasuijin (water god) in various places in Japan (as discussed below in ) If the primordial
kappa was a
Shinto deity, it would fit well with the model that the
Yama-no-Kami (mountain god) can turn into a river god by shifting his spot of residence, as local
kappa (such as
hyōsubo) are purported to exhibit this mountain-to-river seasonal migration behavior, as already discussed in . It has also been speculated that the ("man-shape", cutout paper dolls, etc.) employed as
yorishiro (medium for
spiritual possession) may have influenced the iconography of the
kappa. It is also considered possible that
kappa may have originated from a or a
scarecrow, which squares with the
kappas attributed notion that pulling its right arm shrinks its left. And according to the local lore of
Tōno, Iwate, the redness of the
kappa of this northerly region is ascribable to the creature being a metaphor of economically induced
infanticide (, "thinning").
Bowl or hat origins of dish Regarding the head dish, folklorist
Shinobu Orikuchi's monograph
Kappa no hanashi (1930) delves into the possibility that the
kappas head-dish may have its origins in the
Ta-no-Kami ("rice paddy deity") wearing a conical
kasa type hat. Scholar (1962) (who was
mentored by Orikuchi) extrapolated that if the head covering was the god's umbrella-hat, then the
kappas shell (
carapace) must also represent the
otherworldly god's
mino-type straw cape. Orikuchi's exposition in attempting to argue this point, which is rather a train of thought, is as follows: He first makes comparison with the
kappas head-dish and the folklore about "bowl-lending" (
-gashi), where leaving a note at a certain river-pool or mound causes the necessary number of bowls to be produced on a loan, and since the pool or mound in question is often said to be connected to the
Ryūgū ("Dragon Palace" of the sea god), this must be water deity related lore. A motif within the bowl-lending is that the correct number must be returned, or the blessing will ceased to be given. Orikuchi relates this to dish-counting in
children's songs, and the episode of a woman's voice counting of dishes at the well in the famous
Sarayashiki ("Dish mansion") ghost story. Orikuchi relates this well with the tradition of steeping virgins in mud to propitiate a bountiful rice harvest, which some have believed must have once been human sacrifice rituals, but Orikuchi believed rather to have been a ritual of giving away a woman as bride to the water deity, possibly to be some sort of shrine servant. Orikuchi also brings up the example of the
Hachikazuki ("Bowl-bearer princess") which is part of the
Otogi-zōshi repertoire, opining that such a bowl when expanded into a wider-brimmed hat, can conceivably be like the water deities
kasa-hat, or so summarized by Takahashi, as above. Takahashi in another piece of writing (1939) writes that if one were to pose the question 'What is the
kappas head-dish?' the answer must lie with the or "Pot-Wearing/Crowning Festival" of
Maibara, Shiga, and with the "bowl-lending pool" folklore. Elsewhere, sociologist Muriel Jolivet (2000) has suggested that since the
kappa may be connected to population-control infanticide, the water-retaining depression on its head may have been inspired by the soft
fontanelle spot on a newborn's head.
Wildcat type as migratory legend Kyōgoku and (2000) observes some
kappa fall into the wildcat-type category. They note that in the lore of
Tsushima Island kappa is known either as ('"river tiger") or which do not have the looks of the local Tsushima
leopard cat, but shares the wildcat's behavior. The authors also note that in the Korean language "river tiger" would sound just like (possibly [?],
McCune–Reischauer: , ).
Conflation with kasha Kyōgoku and Tada's older collaboration (2000) also discusses the "
kasha type", where they discuss the possible conflation between the
kasha, which was a dead body-snatching cat-type
yōkai, and therefore comparable to some types of
kappa (which also abducted humans). The comparison is already made by Orikuchi (1930), who cited
Minakata Kumagusu's observation even earlier, that Wakayama Prefecture's local alias for
kappa, the , probably derives from some sort of association with the
kasha yōkai.
Suiko as Chinese name During the
Edo period in Japan, numerous treatises appeared which referred to the
kappa as , a mythical semi-aquatic called by the Chinese in their older
natural history literature. Equating these creatures effectively means they are seen as having a common origin, though there have been notable dissenting opinions on this. An early example is the physician 's , which glossed the water-tiger as . Dissident opinion was given in the encyclopedia
Wakan sansai zue (pub. 1712) which decided the two creatures were different and discussed the Japanese
kawatarō (i.e.
kappa) and the Chinese
suiko/
shuihu as separate entries. However the that appeared only a few years after came to the conclusion that the Chinese
suiko and the Japanese
kappa were one and the same, even though like the
Wakan sansai zue it was built largely on the work of the Chinese
pharmacopeia,
Bencao gangmu. There is a whole family of illustrated treatise on the
kappa that bears the name
suiko in their titles, which drew from early versions and built on them. They bear such titles as ,, , and the single-sheet print . Their chronology and content will be discussed below under . In another example, 's , gives the headline as "Talk on the Ōmi Province
suiko, Talk on the Hizen Province
suiko" but the word
suiko is not actually used in the underlying passages. In the Ōmi Province (
Lake Biwa) anecdote, the lake monster's name is , and in the Hizen Province episode from Kyūshū, the creature is . Yet another example is the antiquary
Yamazaki Yoshishige's As aforementioned,
suiko remains in colloquial usage as an alias of
kappa in certain areas of the Tōhoku region and Kyūshū (e.g., the of Aomori Prefecture). The kappa has also been equated with another mythical amphibian from Chinese literature, called the , mentioned in such works as the ("Records of the Dead and the Living"). In 's (pub. Hōreki 9/1759), equates this
suiin with the Japanese or , while further down also equates the
suiin with the water tiger (
suiko). == Mummies ==