is a Japanese yōkai from the oral tradition of the Kōshin'etsu region. It can also refer to the strange events that this creature causes.
They appear riding on dust devils and cut people using their sickle-like front claws, delivering sharp, painless wounds. The name is a combination of the words itachi meaning weasel, and kama meaning sickle.
Origin
The name was originally thought to be a corruption of the word kamae tachi ("stance sword"), but like the kyūki in the "Yin" part of Toriyama Sekien's Gazu Hyakki Yagyō, they were thus re-used and depicted as a weasel yōkai, eventually becoming established as the yōkai it is now. In the "Mimibukuro" by Negishi Shizumori as well, children in the estate called Kagaya in Edo were enveloped by a whirlwind. Footsteps of a beast remained on the surface of their backs and it was written that this was the proof of a kamae tachi (). As a beast with fur like that of a hedgehog and a cry like that of a dog which flies through the air with wings, they are said to attack people with limbs like that of a sickle or razor.
Legends by area
Devilish winds that cut people are spoken of in the Chūbu, Kinki, and other regions. There are many similar legends passed down in snowy regions and there are some regions where whirlwinds themselves are called "kamaitachi". On occasions of cold wind and other times, it can happen that one would fall and get an inexplicable leg injury.
In the Shin'etsu region, a kamaitachi is said to be the work of an evil god and there is a folk belief that one would encounter calamity by stepping on a calendar. It is counted among the seven mysteries of Echigo.
In the Tōhoku region, when one receives an injury from a kamaitachi, it is said that by burning an old calendar black and putting it on the wound, this would heal.
In Hida, in the Niu River basin, they are said in legends to be a company of three evil gods. The first god would knock down the person, the next god would cut them with a blade, and the third god would put some medicine on it, which is why there is no bleeding or pain. There are also regions that think of these three gods as a parent, child and brother.
In the Yoshio District area of the Nara Prefecture, it is said that when one gets bit by a kamaitachi invisible to the human eye, one would tumble over; even though no blood comes out, there is a big opening in the flesh.
In the eastern part of Aichi Prefecture, they are also called idzuna () and it is said that since an izuna-user once forgot to tell his disciple how to seal an izuna, the runaway izuna would ride on whirlwinds and attack people in order to suck their living blood. It is said that the reason why no blood comes from the wounds from a kamaitachi is because the blood is being sucked away.
In the mountainous regions of Kōchi Prefecture and Tokushima Prefecture among other areas of West Japan, encountering such a strange event is called "being cut by a nogama (, "wild sickle")" and they are said to be caused by grass-cutting sickles that have been left and forgotten in fields and have ended up turning into yōkai. They are also said to be a sickle's vengeful spirit (onryō) that has turned it into a tsukumogami (a receptacle that has turned into yōkai). In the Iya region, Tokushima Prefecture, it is said that sickles and hoes used for digging the grave for a funeral, if left out for seven days, turn into a nogama, and when one encounters a nogama, it is said that one should chant, "beneath the feet on the bottom-left of Buddha, is the stump of a kurotake [a species of bamboo], and quickly became clean, but let it grow back (hotoke no hidari no shita no omiashi no shita no, kurotake no kirikabu nari, itau wa nakare, hayaku routa ga, haekisaru)."
In East Japan, they are also said to be the work of a mantis or longhorn beetle's ghost. In the town of Katakai, Santō District, Niigata Prefecture, in a place called "Kamakiri-zaka" ( or ), after a giant mantis that once lived there was crushed to death by heavy snow, it is said that when one falls over on the hill, because of the mantis' curse, one would receive a wound as if one was cut by a sickle, result in one suffering from black blood flowing out.
In the western parts of Japan, kamaitachi are called kazakama (, "wind sickle") and said to slice off people's skins. There is no pain the instant after it is scraped off, but after a while an unbearable pain and bleeding would start to occur. It is said that one could protect against this by obtaining an old calendar in one's hand.