With their horns, wild hair, fanged mouths, and tiger-skin loincloths, the oni (鬼) are among the most recognizable creatures of Japanese folklore. They are huge, fierce, and often red or blue-skinned, and they carry a massive iron club studded with spikes, the kanabō. They are usually translated as “demons” or “ogres,” and in many stories they are terrifying: man-eaters who raid villages, abduct women, and torment the dead in hell.
Yet the oni are also complex. They can be tricked, defeated, reformed, and even worshipped. They appear in festivals, children’s stories, and proverbs, and every year Japanese families drive them out of their homes by throwing beans.
The Name
The word oni may derive from on, a reading of the Chinese character 隠, meaning “hidden” or “invisible.” In early Japan, oni may have referred to any unseen spirit or supernatural force, including the spirits of the dead and the invisible causes of disease. Over time, under the influence of Buddhism and Chinese demonology, the oni took on a more physical and monstrous form.
Appearance
The classic image of the oni, established by the medieval period, includes:
- Horns, one or two, on the head.
- Red, blue, green, yellow, or black skin.
- Wild, unkempt hair.
- A wide mouth with fangs or tusks.
- Sometimes extra eyes, fingers, or toes.
- A tiger-skin loincloth.
- An iron club (kanabō).
The horns and tiger skin have a symbolic origin. In Chinese and Japanese geomancy, the north-east direction was called the kimon (鬼門), the “demon gate,” through which evil spirits entered. In the Chinese zodiac, the north-east corresponds to the signs of the ox and the tiger. The oni therefore have the horns of an ox and wear the skin of a tiger.
Buildings in Japan often avoided having entrances on the north-east side, and the Enryaku-ji temple on Mount Hiei was built north-east of Kyoto specifically to protect the capital from the demon gate.
Oni of Hell
In Japanese Buddhism, oni serve as the guards and tormentors of hell (Jigoku). They work for Enma, the king of the underworld and judge of the dead, torturing sinners according to their crimes. The most famous are the ox-headed Gozu and the horse-headed Mezu, who guard the gates of hell.
Illustrated scrolls of the Heian and Kamakura periods, such as the Jigoku Zōshi (“Scrolls of Hell”), show oni boiling sinners in cauldrons, crushing them in mortars, and driving them into lakes of fire.
Oni of the Mountains
In folklore, oni also lived in remote mountains and islands, from which they raided human settlements. The most famous oni in Japanese history was Shuten-dōji (“drunken boy”), the king of the oni, who lived on Mount Ōe near Kyoto in the tenth century. With his band of oni, he abducted young women from the capital and ate them.
The emperor sent the warrior Minamoto no Raikō (Yorimitsu) and his four loyal retainers, the Shitennō, to destroy him. Disguised as mountain ascetics, they gained entry to Shuten-dōji’s palace and offered him poisoned sake given to them by the gods. When the oni fell into a drunken stupor, the warriors cut off his head. Even after it was severed, the head flew up and bit Raikō’s helmet. The story, told in illustrated scrolls and Noh plays, became one of the most famous monster-slaying tales in Japan.
Another famous oni was Ibaraki-dōji, Shuten-dōji’s companion, whose arm was cut off by Watanabe no Tsuna, one of Raikō’s retainers, at the Rashōmon gate in Kyoto. The oni later returned disguised as Tsuna’s aunt and took back his arm.
Momotaro and Onigashima
In the famous children’s story of Momotaro, the Peach Boy, the oni live on Onigashima (“Ogre Island”), from which they raid the villages. Momotaro, with his dog, monkey, and pheasant, storms their fortress and defeats them (see Momotaro: The Peach Boy of Japanese Folklore).
Setsubun: “Oni wa soto!”
Every year on Setsubun (節分), the day before the start of spring in the old lunar calendar (usually 3 February), Japanese families perform the ritual of mamemaki (豆撒き), “bean scattering.” A member of the family — often the father — puts on an oni mask, and the others throw roasted soybeans at him, shouting:
Oni wa soto! Fuku wa uchi!
”Demons out! Good fortune in!”
The beans are then eaten, one for each year of the person’s age (or one more), to bring good health in the coming year. Temples and shrines hold public bean-throwing ceremonies, often with celebrities and sumo wrestlers.
The custom has its roots in the tsuina ritual, a demon-expelling ceremony performed at the imperial court on New Year’s Eve from the eighth century, derived from Chinese practice. Beans (mame) were thought to have power against demons, perhaps because mame sounds like ma-metsu, “destroying demons.”
Kind Oni
Not all oni are evil. Some folk tales present oni as lonely, misunderstood, or kind. The most famous is Hamada Hirosuke’s children’s story Naita Akaoni (“The Red Oni Who Cried,” 1933). A red oni wants to be friends with the villagers, but they fear him. His friend, a blue oni, pretends to attack the village so that the red oni can drive him off and win the people’s trust. It works — but the blue oni then leaves forever, so as not to endanger his friend’s new reputation. He leaves a note saying goodbye, and the red oni cries.
Some regions also honour oni as protective spirits, and some festivals feature oni dancers who bless the community.
Oni in Language
The oni appear in many Japanese expressions:
- Oni ni kanabō (鬼に金棒), “an iron club for an oni”: to make the strong even stronger.
- Oni no inu ma ni sentaku (鬼の居ぬ間に洗濯), “doing laundry while the oni is away”: when the cat’s away, the mice will play.
- Oni-gokko (鬼ごっこ), “oni play,” is the Japanese name for the game of tag; the person who is “it” is called the oni.
- Oni can also be used as a prefix for something extreme, such as oni-kawaii, “demonically cute.”
Oni Today
Oni appear everywhere in modern Japanese culture: in anime (Demon Slayer: Kimetsu no Yaiba, whose demons are called oni), manga, video games, films, and advertising. The character Lum in Rumiko Takahashi’s Urusei Yatsura is an alien oni girl in a tiger-striped bikini. From the torturers of hell to the red oni who cried, the oni embody both the fears and the imagination of Japanese culture.
Last reviewed: September 2026.