Myths and Folklore Wiki

Oni also pronounced as ki- as a prefix (Japanese: 鬼 or おに, meaning "hidden, supernatural, fierce, wrathful") also known as kijin (Japanese: 鬼人 fierce person, or 鬼神 demonic spirit) variously translates as: (Ogre, troll, fiend, demon, daemon, devil, evil spirit) are monstrous horned humanoids who are found in countless Japanese stories and myths. They tend to be the enemies of mankind and are generally depicted as roguish villains.

Two famous Oni are shuten dōji and Ōtakemaru.

Myths & Legends[]

Oni are born when truly wicked humans die and end up in one of the many Buddhist Hells, transformed into Oni. They become the ogreish and brutal servants of Great Lord Enma, ruler of Hell, wielding iron clubs with which they crush and destroy humans solely for enjoyment. An oni’s job is to mete out horrible punishments such as peeling off skin, crushing bones, and other torments too horrible to describe to those who were wicked (but not quite wicked enough to be reborn as demons themselves). Hell is full of oni, and they make up the armies of the great generals of the underworld.

Occasionally, when a human is so utterly wicked that his soul is beyond any redemption, he transforms into an oni during life, and remains on Earth to terrorize the living. These transformed oni are the ones most legends tell about, and the ones who pose the most danger to humankind.

The Red and Blue Oni[]

A particularly famous Japanese story about Oni is in regard to two oni friends, and one which wants to befriend humans.

In the story, a red Oni tries to become friends with humans, even writing friendly messages on his house and making sweets. However, Oni are known for being scary, and sometimes being man-eaters, so everyone stayed away. Eventually, he asks his friend the blue oni for help on what he should do to let the humans know he was their friend.

The blue Oni comes up with a plan: he'd pretend to be an evil oni and attack the human village, and the red oni could heroically come in and save the humans by chasing off the blue oni. They enact this plan, and the red oni befriends the humans like he wanted. However, he soon realizes that his friend the blue oni hasn't come around, so he goes to the blue oni's house to see if something happened. He finds a letter from the blue oni, who writes that he will stay away from the humans so that the red oni can still be friends with them (as the humans would recognize him as the "evil" oni that attacked). The story ends with the red oni crying for having lost his old friend.


Oni are one of the most well-known icons of Japanese folklore. They are large and scary, standing taller than the tallest man, and sometimes many times that. They come in many varieties but are most commonly depicted with red or blue skin, wild hair, two or more horns, and fang-like tusks.

Other variations exist in different colors and with different numbers of horns, eyes, or fingers and toes. They wear loincloths made of the pelts of great beasts.


All oni possess extreme strength and constitution, and many of them are also accomplished sorcerers. They are ferocious demons, bringers of disaster, spreaders of disease, and punishers of the damned in Hell.

Modern Depictions[]


Anime and Manga[]

  • In the anime Hozuki's Coolheadedness, the story follows the job of the Oni in Hell.
  • in the anime My Love Story!!, the story of the blue and red Oni are referenced in a school play.

Cartoons & TV shows[]

  • In LEGO Ninjago: Masters of Spinjitzu, the Oni appears as the tenth season's villainous faction. They have also been mentioned and teased to appear in the prior season.

Video Games[]

  • Oni are one of the variety of monsters that can be fought in Okami.
  • Oni is a reoccurring demon in the Megami Tensei series.
  • The character Arataki Itto in Genshin Impact is based on an Oni.


Image Gallery of Oni