 | This articleneeds additional citations forverification. Please helpimprove this article byadding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Raijū" – news ·newspapers ·books ·scholar ·JSTOR(June 2025) (Learn how and when to remove this message) |
InJapanese mythology, theraijū (雷獣, らいじゅう;lit. "thunder animal/beast") is alegendary creature andyōkai associated withlightning andthunder, as well as the godRaijin. It is said to appear with lightning strikes.[1]
Legends of the creature exist throughout Japan, centered primarily in East Japan.[2] Its name appears frequently inEdo period essays and modern folklore materials.[1] One theory suggests that theNue, a yōkai defeated byMinamoto no Yorimasa in theHeike Monogatari, was actually araijū.[2]
Araijū's body is composed of (or wrapped in) lightning. It may also fly about as a ball of lightning (in fact, the creature may be an attempt to explain the phenomenon oflightning, such asball lightning). Its cry sounds likethunder.
Raijū is the companion ofRaijin, theShintogod of lightning. While the beast is generally calm and harmless, duringthunderstorms it becomes agitated, and leaps about in trees, fields, and even buildings (trees that have been struck by lightning are said to have been scratched byraijū's claws).
Another ofraijū's peculiar behaviors is sleeping in humannavels. This prompts the Raijin to shoot lightning arrows atraijū to wake the creature up, and thus harms the person in whose belly the demon is resting. Superstitious people therefore often sleep on their stomachs during bad weather, but other legends say thatraijū will only hide in the navels of people who sleep outdoors.
According to the essayKasshi Yawa [ja] byMatsuura Seizan, when araijū fell with a large ball of fire, a person nearby tried to capture it but had their cheek clawed and was bedridden due to the creature's "poisonous miasma."[3] The same book contains a story about a person in Akita,Dewa Province, who caught araijū that came down with thunder, boiled it, and ate it.[4]
Also inKasshi Yawa, the Edo period painterTani Bunchō stated that humans who are near a lightning strike often lose their minds, but eatingcorn (maize) can cure them. A servant of a samurai family was rendered an invalid after being near a lightning strike, but returned to his senses after Bunchō fed him powdered corn. Furthermore, Bunchō heard from a man who had kept araijū for two or three years that the creature loves to eat corn.[3]
The Edo period ghost story collectionEhon Hyaku Monogatari describes the creature under the title "Kaminari" (Thunder). It states that a beast calledraijū lives in the mountains near Tsukuba inShimotsuke Province (Note: Tsukuba is actually inHitachi Province; this is considered an error in the text). While usually docile like a cat, it runs into the sky with ferocious force when evening storm clouds gather. When this beast damages crops, people hunt it down; the villagers call this "Kaminari-gari" (Thunder Hunting). People have also seen this beast nearMt. Futarasan in Nikkō, and the Edo scholarArai Hakuseki also wrote about this in detail in his essays.[5]
In theKantō region, when lightning struck a rice paddy, people would immediately erect green bamboo and string ashimenawa (sacred rope) around the area. It was believed that as long as the bamboo was there, theraijū could ascend back to the heavens.[6]
TheSengoku period warlordTachibana Dōsetsu was struck by lightning and became half-paralyzed. However, because he continued to fight while riding in a palanquin and showed demon-like strength, a legend was born that he "became paralyzed when he slashed araijū" (or the lightning god).
Since modernization progressed in theMeiji era, the fame of theraijū has declined compared to yōkai and legendary creatures like thekappa ormermaid. However, during the Edo period, theraijū was extremely well known. Because people at the time lacked aviation technology, the sky was a completely unknown world. They could only imagine what existed above the clouds. Therefore, it is said that the legend of theraijū was born from the belief that unknown organisms lived in the sky and fell to earth during natural disasters like lightning strikes.[7]
Raijū are given negative connotations as many things were happening in the sky beyond the reach of humans during theEdo period. While the depths of oceans were also inaccessible to human reason, oceans were helping humans with fishes (food) and sustained life forms. In this sense, phenomena of the sky were transcendental and given negative connotations to the phenomena and the creature.[8]
It is believed that the myth ofraijū originated from the Chinesemateria medica textBencao Gangmu.[8] Additionally, theShan Hai Jing, considered China's oldest geography text, describes a yōkai called theKui (Japanese:Ki) whose bark sounds like crashing thunder; some theories suggest thisKui is the origin of the Japaneseraijū legend.[6] There are also folk customs where belief in indigenousDōsojin andYama-no-Kami (Mountain Gods) merged with theKui god, such as seen in theKuishin statues transmitted at theYamanashioka Shrine inFuefuki,Yamanashi Prefecture.
While broadly described as a white-bluewolf ordog, the appearance of theraijū varies significantly across documents and folklore. It is commonly conceived of taking forms such as atanuki,rabbit,porcupine,bear,squirrel,rat,mouse,deer,boar,leopard,fox,weasel,black orwhite panther,serow,ferret,marten,marine mammal (such aswhale,dolphin orseal),tiger, andcat.[9]
Summarizing its physical characteristics simply, it is often said to be a mammal resembling a puppy or tanuki, about 2shaku (approx. 60 cm) in length, with a tail of 7 to 8sun (approx. 21 to 24 cm) and sharp claws. However, detailed forms and features differ by source:[1]
Stories ofraijū continued into theMeiji era. The *Hokuriku Times* (predecessor to theKitanippon Shimbun) reported in 1909 (Meiji 42) that araijū was captured in Minotani Village,Higashitonami District, Toyama (modernNanto, Toyama). It resembled a cat with mouse-colored fur. When it spread its front legs, "bat-like" flying membranes spread out from its armpits, allowing it to fly over 50ken. It had a large tail that curled back over its face and sharp claws on all legs for climbing trees. It reportedly ate eggs.[11]
In 1927 (Shōwa 2), a strange animal was sighted during a lightning strike onMt. Oyama inIsehara, Kanagawa. It resembled araccoon but the species could not be identified. Because it showed strange behavior every time thunder rang out, it was whispered to be araijū.[12]
Whileraijū in Eastern Japan are described and depicted as mammals, stories fromWestern Japan describe completely different creatures. In particular, strangeraijū legends were transmitted inGeishū (westernHiroshima Prefecture).
A drawing of araijū said to have fallen in Itsukaichi Village, Geishū (modernSaeki-ku, Hiroshima) in 1801 resembles acrab orspider. Its limbs were covered in scales with large pincer-like tips. It was said to be 3 shaku 7 sun 5 bu (approx. 95 cm) long and weighed over 7kan 900monme (approx. 30 kg). TheKikaishū from theKōka era also records the corpse of a similarraijū that fell in Shiogama, Kokonokaichi-no-sato, Geishū on May 10, 1801 (see image). Despite slight differences like "Itsukaichi" vs "Kokonokaichi", these are considered the same event. Furthermore, there is a drawing of araijū dated May 13, 1801, also having pincer-tipped scaled limbs, accompanied by a description of features indistinguishable from the drawing alone: "Face like a crab, forehead has whorled hair, has four legs, like bird wings, scales grow, has hooked claws like iron."[7]
InInshū (modernTottori Prefecture), a drawing remains of a beast said to have fallen in the castle town at dawn in May 1791 (Kansei 3). It measured 8 shaku (approx. 2.4 meters) long, with sharp fangs and claws. Because its body shape resembled aseahorse, it was named "Rairyū" (Thunder Dragon) instead ofraijū (see image).[7]
From cases like these, some view "Raijū" as a general term for phantom beasts that fall during lightning storms, with no fixed appearance.[7]
Dead animals were found from under trees after a stormy night in Japan. Attempts were made to debunk this myth. It was claimed that deadraijū are essentially real dead animals startled or knocked off from the tree during tempestuous weather of Japan.[8]
One theory suggests that the true identity of theraijū is themasked palm civet (Paguma larvata). Characteristics recorded in various classical texts—such as size, appearance, sharp claws, tree climbing, and scratching trees—align with the masked palm civet. Descriptions ofraijū shown in sideshows in Edo also match this animal. It is inferred that because masked palm civets were rare in the Edo period and did not yet have a standardized Japanese name (like "hakubishin"), they were regarded asraijū.[13][14] Experts have pointed out that drawings ofraijū in Edo period books depict masked palm civets.[15]
While masked palm civets are native to southern, eastern, and southeastern Asia, some scholars believe they were brought to Japan by soldiers duringWorld War II as pets.[8] However, the resemblance ofraijū in Edo period paintings to the civet suggests they have been present in Japan much longer.
Another theory posits theJapanese marten as the true identity due to its size (close to a dog or cat), but since martens live in forests rather than the developed downtown areas of Edo, this is considered less likely.[13] Other theories suggest the legend was imagined from animals likeflying squirrels (momonga) falling from trees in shock from thunder,[7] or misidentifications ofweasels,giant flying squirrels (musasabi),badgers,otters, orsquirrels.[16]
InShinano Province during the Edo period,raijū were called "Thousand-year Weasels" and were displayed atRyōgoku. These have been pointed out to be fakes crafted from weasels or badgers.[6] Araijū sideshow also existed in Otowa,Hoi District, Aichi (modernToyokawa, Aichi), which is similarly pointed out to be a badger.[4]
At the treasure hall ofSaishō-ji Temple inSantō District,Niigata Prefecture, a "Raijū Mummy" is preserved as a temple treasure and is open to the public.[17] Its origin and legend are unknown, but it has a cat-like appearance, is about 35 cm long, and is posed in a threatening stance with bared fangs.[7] Yōkai researcherKatsumi Tada viewed this mummy and stated it was "just a cat."[6] While there are many mummies in Japan attributed tomermaids oroni,raijū mummies are rare.[17] InShizuoka Prefecture, a mummy wrapped inwashi paper written with "Raijū" in ink was found in the storehouse of an old family; its origin is also unknown.[7]
Yūzan-ji Temple inHanamaki, Iwate also has a beast mummy with a tag reading "Raijin" (Thunder God), which is regarded as araijū. At a glance it resembles a cat, but its limbs are abnormally long compared to a cat, and its head lackseye sockets, suggesting it is clearly distinct from ordinary biology.[18]
Fuji Shrine (written with characters for "Wisteria") in Imayo-cho,Higashiōmi, Shiga, is a rare shrine that worships araijū. Legend states that the village once suffered from frequent lightning strikes. A passingYamabushi declared that araijū living in the village was the cause. He had the locals build a large net and set it in the forest on the village outskirts. When black clouds formed and thunder began, a red-black beast appeared on the net. The yamabushi immediately caught it—it was a dog-like beast with a beak and sharp claws—and beat it to death with an iron staff. He declared his duty done and left. The lightning ceased, and a shrine was built in the forest where the beast was caught. This shrine was called "Fūjikome" (Sealing) Shrine to signify sealing theraijū, and the characters were later changed to "Fuji".[19]
{{cite web}}: CS1 maint: multiple names: authors list (link)| Mythic texts |   | |
|---|---|---|
| Japanese creation myth | ||
| Takamagahara mythology | ||
| Izumo mythology | ||
| Hyūga mythology | ||
| Human age | ||
| Mythological locations | ||
| Mythological weapons | ||
| Major Buddhist figures | ||
| Seven Lucky Gods | ||
| Legendary creatures | ||
| Other | ||