Oni

Somewhere near the Akuta River, a man who has stolen a woman far above his station puts her inside a ruined storehouse and stands guard at the door with his back to her, because a thunderstorm has come down and there is nowhere else to shelter. She screams once. The thunder covers it. When the sky clears and he looks in, there is nobody there at all. The sixth episode of the Tales of Ise, written down by the middle of the tenth century, does not show him anything, and it does not need to. The reader already knows the phrase. Oni hitokuchi, an oni in one gulp.

Nothing is seen in that story, and that is the oldest and most important fact about the oni. The character now used for them, 鬼, is Chinese, and in Chinese it means the invisible soul or spirit of the dead. Wamyō ruijushō, the first Japanese dictionary, compiled in the 930s, derives the word from on, hiding, and glosses it as something hiding behind things, not wishing to appear. In the very earliest Japanese texts the same character is more often read mono, a spirit felt rather than met, the same mono that sits inside mononoke. Whatever the ancient Japanese were afraid of in the mountains and the dark, it had no face yet.

It also had no single name, and this is worth being plain about. Oni is an ordinary noun. It is a category, not a biography, and the tradition never settles on one oni any more than European tradition settles on one devil. What the word does is absorb. Evil kami, epidemic spirits, hell’s wardens, household objects that reached a hundred years old and came alive, angry ghosts and living rivals all get filed under it at one point or another.

The oldest sightings sit in the official records, which is itself a comment on how seriously they were taken. The Chronicles of Japan, completed in 720, report that in 544 people from the north came ashore on Sado island and the islanders would not approach them, believing they were oni, and while they hesitated some of them were carried off. Those people were almost certainly a foreign group. The Izumo topography of 733 has a one-eyed oni appear in newly cleared ground at Ayo and eat a man who is working the field. The True Records of Three Generations, compiled in 901, describe three women walking near a hall inside the palace compound in 887, one of whom stops to talk with a handsome man beneath a pine. When the other two look back, her limbs are lying on the ground and her head is gone.

The body came later, and it came from abroad. Buddhism brought a whole population of ready-made devourers: yaksha, who drain a person’s vital force and eat the flesh, and rakshasa, who eat flesh and drink blood, both attendants of Bishamonten, along with hell’s ox-headed and horse-headed wardens and the trampled figures ground under the feet of the Four Heavenly Kings at temple gates. Chinese ghost imagery gave shape to something that had never had one, and the shape barely changed on the way across. Onmyōdō, the court’s yin and yang practice, supplied the other half, an oni that was still invisible and still caused illness, along with the suspicion that the diviners themselves could see them and even make them. One medieval account holds that the spirits abandoned by practitioners such as Abe no Seimei under Modoribashi bridge became the oni who walk the capital on certain nights.

By the time the Tales of Times Now Past was compiled around 1120 the horns are there. So is a particular anatomy that stays remarkably stable across the picture scrolls: two or three fingers on each hand, two or three toes on each foot, the nails long and sharp. An oni met at Agi Bridge is nine feet tall, greenish, and wears its hair loose and wild. One seen in 929 is taller than a house beam. The arm that comes off one of them in an early version of the Tale of the Heike is black and covered in white hair, and the Great Mirror gives a shaggy hand with knifelike nails. The colours, the rage-swollen faces and the loincloths come out of the hells and hungry-ghost scrolls. The tiger skin and the ox horns are usually explained by a pun: the unlucky northeast was called ushitora, ox-tiger, and also kimon, the demon gate, so the oni got the horns of one animal and the pelt of the other. The famous iron club is a latecomer. Ancient and medieval oni hit people with hammers, and they are not drawn swinging clubs until the Edo period, which is also roughly when everyone stopped believing in them.

What no scroll can draw is the ability the stories care about most. An oni changes shape. At Agi Bridge it waits as a beautiful young woman until the swaggering traveller is close enough, shows him the green skin and the three fingers, loses him, and then comes back to his house wearing the face of his younger brother, and that time it does not lose him. The best-known version happens at Modoribashi. Watanabe no Tsuna, one of Minamoto no Raikō’s four guardians, is riding home with his lord’s sword when a woman of about twenty asks to be taken to her house. He lifts her onto the horse. A hand closes on his topknot, the ground drops away, and a voice announces that he is going to Mount Atago. He cuts, and falls, and is left holding an arm. Days later his foster mother visits and asks, warmly, whether she might see the famous arm. He opens the chest for her.

The oni’s greatest star does the same trick at greater length. Shuten Dōji, whose oldest surviving text is a fourteenth-century illustrated scroll held by the Itsuō Art Museum, is a boy by day and a horned monster by night, and he holds a mountain palace where the kidnapped daughters of the capital are butchered and served at banquets. Raikō and his men arrive dressed as mountain ascetics, are received with real courtesy, and repay it with drugged sake and a beheading. The severed head is shown flying up to bite the helmet of the man who tricked it. A booklet sold at the oni museum in Ōe captions that picture with a line that has been quietly ruining the story’s moral clarity for centuries: there is nothing false in the words of demons.

Not every oni is an enemy. In one strand of Japanese thinking they are close relatives of the marebito, powerful strangers who arrive from beyond the sea at New Year, are treated generously and leave blessings behind, which is why oni turn up in comic theatre handing over wealth and why the city of Kitakami can describe them as ancestors who protect the townspeople and good deities who bring happiness. Even the bean-throwing at Setsubun, which descends from a Chinese court rite for expelling plague spirits, treats them as something that can be sent away by household means rather than fought. Roasted soybeans and a shouted demons out will do it.

The uncomfortable part is how often the word landed on people. It was used for the northerners on Sado, and for the strangers who came ashore in Izu in 1172, whom the courtier Fujiwara no Kanezane privately judged to be simply foreigners. It was used for infants born with unusual bodies, who were called oni children and abandoned as a danger to the state. From the Kamakura period onward it attached itself to women, especially jealous or spurned ones, until the Noh stage was full of them. In the twentieth century it was painted onto Russian, British and American soldiers, and Japan’s first feature-length animated film, released in April 1945, gave the demons of Demon Island one horn each and Western faces.

Their powers are consistent with all of that. They eat, they transform, they throw lightning, they are enormously strong, and they can enrich a house that treats them properly. Their weaknesses are consistent too, and they are mostly social. An oni can be flattered, feasted, seduced and got drunk. It can be cut, and the wound stays. It can be bound by spells, trodden underfoot by Buddhist guardians, and evicted by a handful of beans. Above all it depends on the dark and on being believed in, and it lost both. Skepticism set in during the Muromachi period, the Edo townsfolk turned oni into souvenir paintings of a demon piously chanting the Buddha’s name, and electric light finished the job. They have relocated. There is a two-car train in Iwate painted with a plump, cross-looking oni whose job is to bring tourists north.

Frequently Asked Questions

What is an oni?

An oni is a demon or ogre of Japanese tradition, usually described as a large, horned, brightly coloured humanoid that eats people and changes shape at will. Oni are a whole class of beings rather than one named figure, and the word was historically applied to anything hostile, invisible or foreign, including sickness, storms and human outsiders.

What does an oni look like?

The standard medieval and later oni has one or more horns, red, blue, black or yellow skin, a wide mouth with prominent fangs, wild hair, and hands and feet with only two or three clawed digits. It is usually shown nearly naked in a tiger-skin loincloth, a detail often explained by the northeast being called the ox-tiger direction and the demon gate. The iron club it carries in modern pictures only appears in the Edo period.

Are oni evil?

Mostly, but not entirely. Oni are best known for cannibalism, abduction and disease, yet another strand of Japanese tradition treats them as visiting outsiders who bring wealth and good fortune, and some communities in northern Japan regard them as protective ancestral spirits.

How do you get rid of an oni?

Roasted soybeans thrown at the Setsubun festival while shouting for demons to get out are the everyday method, inherited from a Chinese court ritual for expelling plague spirits. In the stories oni are also killed by warriors who trick them, most famously Minamoto no Raikō, who got Shuten Dōji drunk on drugged sake before beheading him, and Watanabe no Tsuna, who cut the arm off an oni at Modoribashi bridge.

What is the most famous oni story?

The tale of Shuten Dōji, the demon of Mount Ōe who kidnapped and ate the daughters of the imperial capital until Minamoto no Raikō and his four retainers destroyed him. Its oldest surviving version is a fourteenth-century illustrated scroll, and the episode where the severed head flies up and bites the hero’s helmet is the single most reproduced image in Japanese demon lore.

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Shuten-dōji, Kijo, Namahage, Ushi-oni, Amanojaku, Yomotsu-shikome, Tsuchigumo, Yōkai, Tengu, Raijin, Gaki, Shikigami, Abe no Seimei, Yaksha, Rakshasa