ONI 鬼

Pronunciation: OH-nee

Translation: Ogre or Demon

Similar to: Kijo (鬼女), Yamauba (山姥), also pronounced Yamanba; both female oni

Overview

Oni is often translated as “ogre” or “demon,” but those monikers don’t do justice to these complex Japanese beasts. The basic oni as they appear these days are ogre-like monsters many times larger than humans, heavily muscled, with skin tones of red or blue (or sometimes green). They have two horns on their heads, extremely fierce expressions on their faces, and sharp fangs. Naked from the waist up, they’re usually seen wearing tiger-skin loincloths and iron rings around their ankles and wrists. They carry studded iron clubs. Not that they need them—oni are unbelievably strong, voracious, bloodthirsty, and, except for a few outliers, downright evil.

Oni of old, though, were actually more diverse. They appeared in a greater variety of colors (black, white, yellow, multicolored) and had any number of eyes, from one to dozens, and there were even some that were one-legged. Then there were oni that were more or less invisible wicked entities up to no good.

Oni were originally from China but have taken on a life of their own in Japan, evolving through the ages. There are several lineages of oni that are still debated by scholars and folklorists. One obvious origin story can be found in the mythical beginnings of Japan. A kind of pre-oni race called the yomotsushikome (黄泉醜女), which means “fearful creatures of the underworld,” was mentioned in the Kojiki (C.E. 712) as a band of terrible ogre-like monsters sent to avenge the divine female creator of Japan, Izanami. (You can find more on her story in the Raijin and Fūjin entry.)

A second genesis of the Japanese oni myth is Buddhism. Buddhist hells are especially grotesque and ghastly. If you’re ever unfortunate enough to find yourself in one, you’ll first be met by Gozu (牛頭) and Mezu (馬頭), which are a cow-head oni and a horse-head oni. Once inside, a plethora of other heinous oni will be waiting to skewer you with long blades, pour boiling iron all over you, or stir you into a pot of pus and blood for the rest of eternity.

Then there’s also the esoteric practice of Onmyōdō, where powerful onmyōji (mystical diviners) can conjure and control shikigami (式神), which are also called kijin (鬼神), whose characters mean “oni” and “god.” Onmyōji are rumored to create these demon beasts, too, and manipulate them as needed.

Background and Popular Stories

One of the most famous folktales about an oni is the story of Shuten Dōji (酒呑童子), whose name means “Sake Drinking Lad.” But Shuten Dōji was no innocent lad—he was 50 feet (15 meters) tall and by some accounts had a crimson-colored body, five horns on his head, and fifteen eyes. Rumor had it that Shuten Dōji’s father was Yamata no Orochi, the eight-headed dragon. Shuten Dōji was and still is considered the strongest and most loathsome oni in Japan’s history. His tale goes something like this.

Once upon a time, back when Japan’s capital was Kyoto, women and young girls started disappearing from the streets and even their own homes. The famed onmyōji Abe no Seimei was consulted, and it was determined that the culprit was a heinous oni named Shuten Dōji and his group of lesser ogre who lived up on Mount Oe. This savage gang were notorious for getting drunk, kidnapping young women, and both drinking their blood and eating their flesh. The legendary Minamoto no Yorimitsu (源頼光) (C.E. 948–1021) was called, along with his Shitennō (四天王), or Four Heavenly Kings, the famous band of samurai Yorimitsu always fought with (one of them being Sakata no Kintoki—see the Kintarō entry). Disguised as monks, the five samurai hid their weapons inside their billowy robes and prepared to defeat the monster.

After praying at a couple of shrines, the warriors set out. Still not exactly sure what their plan was and deep in the mountains, they were met by several old men (who were actually gods in disguise). The elderly deities presented the men with a jug of magical sake and some advice. If Shuten Dōji—who drank constantly but never lost consciousness—were to consume this divine drink, he would, in fact, pass out. The rest was up to them.

Later that night, gathered around the abominable feasting table, Minamoto no Yorimitsu secretly served the charmed sake to Shuten Dōji and it worked. Once the giant was asleep, Minamoto no Yorimitsu chopped off his head. But instead of falling to the floor, the enormous head flew at Yorimitsu, gnashing its teeth. It latched on to the warrior’s helmet and bit down. Luckily, the great samurai just happened to be wearing two helmets that day. Eventually, the five samurai defeated the beast and his minions and rescued all the kidnapped—not yet eaten—young women and took them home.

Another interesting superstition about the oni involves the northeastern sections of homes, buildings, and even cities. This area is called the kimon (鬼門), or demon’s gate, and it is believed to be very unlucky. The belief system of Onmyōdō posits that it is here yin energy changes into yang energy, thus making it unstable and chaotic. Other theories hold that it’s the direction from which the coldest winds in the winter blow or that it’s where spirits pass through. Whatever the reason, the kimon is the place where oni come into your home, steal all your good luck, and unleash adversity.

The topic is quite complicated, and there are more than a few differing belief systems, but as a general rule, when building a house, you should never put a window, door, or anything related to water (such as a toilet) or fire (such as a stove) in the northeast part of the house. Windows and doors make it easier for the oni to enter, and fire and water rile up the demons, making them more dangerous. In Japan, contractors are aware of this superstition and will help design your home accordingly. If all else fails, a well-placed ofuda (お札) (talisman) or a monkey or blue dragon figurine might help ward off the misfortune-bringing ogres.

In older times, entire cities were planned in order to protect this vulnerable sector. Kyoto’s Enrakuji complex on Mount Hiei was built on the kimon of the city in hopes that the positive power of the temples would dispel any oni with malicious intent. If you walk around the Kyoto Imperial Palace, you’ll notice it is notched—the northeast corner actually has an indentation that symbolically erases the dangerous gateway for bad luck.

Other ways to help protect yourself from oni include keeping your kimon clean and placing some lucky items there, or planting a prickly holly bush in your yard (oni dislike thorny leaves).

February 3 in Japan is Setsubun (節分), or Bean-Throwing Day, marking the transition from winter to spring. On this day, families all across Japan throw handfuls of roasted soybeans outside, yelling, “Oni wa soto!” (Oni, outside!), and then toss more beans inside with the call, “Fuku wa uchi!” (Good luck, inside!). Sometimes people will dress up as oni on this day and children will pelt them with soybeans. Also, on Setsubun, people eat the same number of soybeans as their age to ensure good luck and health in the coming year.

In Modern Stories

Despite their nastiness, Oni are everywhere in popular culture. Some places you might have seen them are the manga and anime Inuyasha and Demon Slayer and the Netflix show Oni: Thunder God’s Tale. Although the show is called Oni: Thunder God’s Tale, the main character Naridon is actually Raijin (see the entry on Raijin and Fūjin).