The Meaning Behind the Name
Kanji:雷獣 (Raiju, meaning “Thunder Beast” or “Thunder Animal”)
The Raiju’s Physical Appearance
The Raiju is a divine beast intimately connected with lightning and thunder. Beyond that basic fact, Raiju are one of the most difficult yokai to definitively describe. There are many, many Raiju legends, but this actually makes describing the Raiju more difficult, as each legend records a different appearance!
The most popular depiction of Raiju is as a wolf. Either a blue and white wolf, a wolf surrounded by bolts of lightning or a wolf made entirely out of lightning, with a howl like the rumble of thunder.
And yet, Raiju are also reported to be similar to other (less imposing) mammals as well, including dogs, weasels, badgers, monkeys, tanuki, foxes and even cats… There is even a legend in which it is a small dragon-like creature, and another in which resembles a crab.
Finally, some legends just describe the Raiju as formless, a ball of fire or pure lightning.
With all these different reports, perhaps this chimerical creature’s form is as variable as the clouds it inhabits…
The various reports from people who have captured and raised Raiju say they like corn, eggs or small insects. However, the Raiju is probably carnivorous, as all the species it is said to resemble are also carnivorous.
Raiju like to sleep inside people’s navels (note: not sure how this works, maybe they shrink to a small size…) Otherwise, the raiju accompany the shinto Thunder God Raijn in the sky, hiding in the clouds.
During thunderstorms, however, Raiju descend from the sky, accompanying lightning to strike at trees and houses. Especially in the Edo Era, when the houses were mostly made of wood, a lightning strike could spell disaster. The unpredictable nature of the stikes made people fear them all the more. Thus, Raiju attacks were also believed to be a form of divine punishment: those whose homes were struck by lightning were “suffering the wrath of the Raiju”.
Raiju are mostly harmless, except during lightning storms, when they grow wild, running amok in fields and forests. The scorch marks left behind on trees and homes from a lightning strike were believed to be the claw marks of the Raiju. During storms, they were said to attack people who are sleeping beneath trees, and to enter houses which are unprotected. Therefore, some people used to cover their windows, doors and chimneys with mosquito netting, which it cannot pass through. Also, the raiju dislikes the smell of incense, and will avoid those houses which have a tradition of lighting incense during thunderstorms.
When they sleep in a person’s navel, the Thunder God Raijin will shoot bolts of lightning at the Raiju to wake it up, but killing the person whose navel it was sleeping in. Thus, superstitious people will sleep face down during a thunderstorm to avoid being killed by a lightning strike.
Finally, one legend says that eating the bark of a tree struck by a Raiju (so blackened by lightning) can cure toothache.
The Origins of the Raiju
Traditionally, the Raiju is a companion of Raijin, the Japanese Shinto God of Thunder, in a role akin to that of a pet. It may be an attempt to explain lightning phenomena, such as the lightning ball, or to justify the existence of lightning strikes.
The origins of the Raiju may also stem from China, as the ancient Chinese herbology text, the Compendium of Materia Medica or Bencao Gangmu mentions a wolf with a howl like thunderclap.
A final theory is the possibility, the Raiju legends began with the deity god of Yamanashioka Shrine in Fubuki City , Yamanashi Prefecture.
The Raiju as a Real Animal
Unlike most yokai, there are quite a few accounts of people capturing Raiju and even using them as sideshow attractions. The Temple of Tenjin in Matsue put one such Raiju on display (for an entrance fee), in a brass cage. The Raiju looked like a badger, slept during fair weather, but during storms it was restless in its cage, with flashing eyes.
In the Edo era, traveling shows would also sometimes display creatures they claimed were Raiju, either live in cages, or dead, in glass boxes. The creatures would supposedly grow wild in their cages during thunderstorms like Raiju, although that might easily be explained by the fact that most animals are frightened during storms.
Most yokai are elusive, remaining rarely seen elements of folklore. So how to explain the frequent sightings and capturings of the “Raiju”? One theory is that the animals reported could simply be a variety of small mammals, such as cats, badgers, otters or weasels. In particular, sideshows may have captured random wild animals which they then labelled as “Raiju” so they could make a profit.
Likewise, the mummified Raiju bodies enshrined in temples and shrines even today, may also just be some kind of small taxidermied mammals…
If the legends of the Raiju were inspired by a specific mammal, then the masked palm civet or hakubishin (Paguma larvata) is a good candidate. The civet was brought over from the Asian mainland in the Edo era. Since it looked unlike any of the other mammals commonly found in Japan, perhaps its unusual appearance led people to believe it was a mythical creature. Another animal that might have inspired the Raiju, is the flying squirrel. When startled by lightning strikes, the squirrels could have fallen out of the trees, thus inspiring the legend.
Recorded Raiju Legends
Raiju have been recorded in various manuscripts throughout Japanese history, the earliest of which date back to the beginning of the Edo Era.
Early Edo Era Raiju Legends and Sightings
In the Edo Era, the sky was a place filled with the unknown, completely inaccessible, the domain of mysteries and divinities. Furthermore, lightning strikes, their targets completely arbitrary and unpredictable, filled people with fear. So stories explaining the origins of these strikes became very popular. Here are some of the most famous!
The Shinano Chikoku
The Shinano Chikoku describes the Thunder Beast of Shinshu (now Nagano Prefecture). It records the beast as having the size and appearance of a grey colored puppy, with a long head, a tail thicker than that of a fox and the claws of an eagle. The book also records another raiju in Nagano’s Tateshina mountain, which also looks like a puppy, with the hair of a badger and the claws of an eagle.
The Gendo Hogen
In the 玄同放言 (Gendo Hogen) by Kyokutei Bakin, the raiju is described as a wolf with two front legs, four back legs and a tail split into two branches. See below:
The Shunkuni Magazine
According to the Shunkuni magazine (駿国雑誌), locals spotted a Raiju was in Suruga Ekiatama County Hanazawa village Takakusayama (now Shizuoka Prefecture Fujieda). The Raiju was about 60 centimeters long, with chestnut colored fur, similar to a weasel or a cat, with a long tail. It flew in the sky and during thunderstorms it tore up trees.
The Hokkaido Shidan
The Edo Era article Hokkaido Shidan says the Thunder Beast of Shimonoyama Kuniyama (now Nasuyama City , Tochigi Prefecture), looked like a rat, but was larger than a weasel and had very sharp claws. In the summertime, it says the Raiju headed to the top of the mountains to look for clouds to ride. When it leapt from the mountain tops to the clouds, the clouds would rumble with thunder.
The Echigo Nayoro
The encyclopedia Echigo Nayoro relates that, in what was once the Country of Echigo (and is currently Niigata prefecture), a beast landed on the property of the Masushiro samurai family. It was injured from falling from the sky, so the family was able to capture it. Upon closer observation, it looked like a cat in shape and size. However, unlike a cat, its hairs were shiny grey, turning golden in the sunlight. Its stomach hairs ran in the reverse direction, while each the tip of each hair was divided in two. After the creature had healed, the family released it.
The Kotoko Koda
In the Edo period essay Kotoko Koda there was a raiju that descended in Akita. It described the raiju as similar to a tanuki, but with longer and darker fur.
Tomoaki Yamaoka’s Records
According to the Kokugaku scholar Tomoaki Yamaoka (山岡浚明), a certain Izumiya Kichigoro managed to capture a Raiju in an iron cage. The beast resembled a mole, with the snout of a boar and the belly of a weasel and survived on a diet of snakes, crickets, frogs and spiders.
The Ehon Hyaku Monogatari
The yokai illustration book, the Ehon Hyaku Monogatari (絵本百物語, “Picture Book of a Hundred Stories”) describes the Thunder Beast as follows: “A beast called a thunder beast lives in the mountains near Tsukuba in the land of the wilderness. Although, it is usually quiet like a cat, it rushes into the air with tremendous force when the evening clouds appear. When the beast destroys crops, people hunt it. There are people who have seen this beast near Mt. Futarayama, and Arai Shiraishi, a scholar from the middle of the Edo period, wrote this in detail in an essay.” Below is the depiction of the Raiju from the Ehon Hyaku Monogatari:
Tani Bunsho’s Records
The Edo period painter Tani Bunsho, writes that those near the location of a lightning strike may lose their wits in fear. There is a cure though. Those who go insane after meeting a Raiju will regain their sanity if they eat corn powder. Tani Bunsho tells the story of a servant of a certain samurai. On one journey, lightning struck, nearly hitting the servant, who then lost his wits. The samurai abandoned his servant, but the man recovered after eating corn powder.
The Koshi Yoroku
According to Matsura Shizun ‘s essay “Koshi Yoroku”, a thunder beast fell along with a ball of fire. A passerby tried to catch it. But instead, the Raiju gave the man a poisonous scratch on the cheek. Matsura Shizun also mentions that in Dewa- gun, in Akita, someone caught, cooked and ate a lightning beast that fell down during a thunderstorm.
Tachibana Dōsetsu’s Legend
A legend about the samurai Tachibana Dōsetsu, says that he was once resting beneath a tree, when lightning struck it. He drew his sword and slashed the bolt of lightning, revealing a dead Raiju. After this incident, he named his sword “raikiri” or “lightning cutter”.
The Heike Monogatari
The Heike Monogatari describes the attack of the chimerical yokai Nue on Kyōto in 1153. The samurai Minamoto no Yorimasa defeated the yokai. However, according to the 斉藤小川町, that yokai might actually be a Raiju instead of a Nue.
The Oshu Raiju
The Lake Biwa Raiju
In 1802, in Lake Biwa on the island of Chikubushima, another Raijū supposedly fell. It had four legs, similarly sharp fangs and webbed toes. Its body was about 75 centimetres long.
The Banshu Raiju
In June, 1806, in Banshu (now Hyogo Prefecture ) a Raiju fell near a local castle. It was about 40 centimetres long, with fangs and webbed toes. However, the artist only drew the upper body of the creature, so we cannot be sure if they only found the upper half, or if the artist only chose to draw the upper half.
The Hidden Monsters Collection
A rare, non mammalian, Raiju fell into the Geisho Itsukaichi area (currently Saeki-ku , Hiroshima Prefecture) in 1801. The beast’s shape was reminiscent of a crab or spider, while the surface of its limbs was covered with scales. It measured about 95 centimetres and weighed about 30 kilograms. The Hidden Monsters Collection or 奇怪集 records a similar beast (or possibly the same beast), which dropped onto Sato Shion in Geishū (today Hiroshima) on May 10 in 1801. Below is the drawing from the Hidden Monsters Collection:
Meiji Era Raiju Sightings and Legends
In the Meiji Era, the introduction of technology and science from abroad increased the general population’s understanding of the nature of electricity and thus lightning. Furthermore, the appearance of airplanes decreased the mystique of the skies, the supposed domain of the Raiju. Superstitions were gradually abandoned, and along with them the legends of the Raiju. However, there are still two reports of possible Raiju sightings from this era:
The Hokoriku Times
The Hokuriku Times reported that a thunder beast was captured in Sugaya Village (now Nanto City ) in Higashinami- gun , Toyama Prefecture in 1909. The beast resembled a cat, with scarlet fur. When its the front leg extended, a bat-like webbing spread out from underneath its arms, letting it glide (like a flying squirrel?). The creature’s tail bent backwards (also like a squirrel?). Its fore and hind legs had sharp claws, for climbing trees. Finally, its diet consisted of eggs.
The Oyama Raiju
In 1927, people spotted a strange animal during a lightning strike at Mount Ōyama. People of the nearby Isehara City, in Kanagawa Prefecture, then began to worship the animal. Because the animal behaved oddly during thunderstorms, rumours spread that it was a Raiju.
Local Raiju Legends
The Fuji Shrine’s Raiju
The Fuji Shinto Shrine in Higashi-Omi-shi, in Shiga Prefecture, is a Shinto shrine with a historical relationship to a Raiju. The village used to suffer from frequent lightning strikes, until a passing yamabushi (mountain hermit) told the villagers that the lightning strikes were caused by a Raiju which had settled down near the village.
The locals made large nets to capture the Thunder Beas, then brought them to the forest where the Raiju was hiding. Upon arrival, a black cloud formed in the skies above them, accompanied by the sound of thunder. Suddenly, a red and black beast appeared in the net. It’s form was dog-like, but with a beak and sharp claws. The yamabushi hit the beast with an iron rod, killing it. His role completed, the yamabushi left the village.
Since then, the village has had no lightning strikes, and a shrine was set up in the forest where the beast was caught. The shrine was called the “Fujikome Shrine” because it sealed the Raiju, although the name was later changed to “Fuji Shrine”.
The Kanto Region
In the Kanto region, when there is lightning, people would set up an enclosing rope or Shimenawa (the kind that can be seen in Shinto Shrines) around green bamboo. With the bamboo, they believed the Thunder Beast would then be able to rise back up into the sky.
In Inshu (now called Tottori Prefecture ), there is a drawing of a beast that fell near the castle in the early morning of May in 1791. It was about 2.4 meters long, with sharp fangs and claws. It was named the “Thunder Dragon” since it resembled a seahorse or small dragon. The drawing is below:
Real Raiju Mummies!
In Japan, there are a number of mummified specimen, which are supposedly of yokai, mainly those of ningyo, oni or kappa. Raiju specimens are much more rare, however, there are still a few kept in shrines and temples across Japan:
- The Oyama Temple in Hanamaki City Iwate Prefecture, has put on display the mummy of a mysterious creature which is labelled as a “Thunder God”. It is usually believed to be a kind of Raiju. The creature is similar to a cat, but its limbs are unusually long compared to those of a cat. Those who believe that the mummy is that of a Raiju, claim that the body is different from those of ordinary mammals because of the length of its limbs, and because its skull has no eye sockets.
- In the Saisei-ji i Temple in Mishima-gun , Niigata Prefecture, one of the temple treasures is supposedly the mummy of a Thunder Beast. The mummy is displayed to the public in the treasure hall of the temple. The mummy’s origins are unknown, but it looks like a cat baring its fangs, and is about 35 cm long. When the yokai researcher Katsumi Tada visited the mummy he said that he believed the animal to simply be a mummified cat…
- In Shizuoka Prefecture, someone found a mummy covered in washi paper in a storehouse of a certain old house. On it was the label “Raiju”, although the beast’s actual identity and origins remain a mystery.
The Raiju in Modern Media
Today, the Raiju had fallen into relative obscurity, when compared with yokai like the Kappa or the Tatsu. And yet, the Raiju still appears in some media today:
- In the film Pacific Rim, the name of one of the the kaiju (giant monsters) is Raiju. Although, it does not resemble the yokai raiju at all, being a giant crocodilian creature, and also does not have any relationship with lighting or electricity.
- In Naruto: Shippuden, Kekkaishi uses a technique that creates a wolf made of lightning, reminiscent of a Raiju.
- The Legendary Pokémon Raikou is similar to the Raiju, as it has electric abilities and appears only during thunderstorms. Other similar Pokémon are : the wolf-like Manectric, the lion-like Luxray and the cat-like Zeraora. The name of the electricity using, mouse-like Raichu might also have been inspired by the Raiju.
- Raika in rosario +vampire is a Raiju.
- In Digimon, the raidramon Hiten
- Manten from InuYasha
- The Thunder Card in CardCaptor Sakura has the form of a Raiju.
- The Raiju appears as a character in Kemono Friends
- In Monster Hunter the monster Zinogre may be inspired by the Raiju
- In Kyogoku Natsuhiko’s “Kami-nari” 前巷説百物語 (One Hundred Stories)
Have you seen the raiju in any other media? If so, let me know below so I can add it to the list. And if you want to learn more about other yokai, see here!
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