onni

Oni are a class of supernatural beings in Japanese folklore and Buddhist-inspired myth. The standard English spelling is "oni," though some older texts or nonstandard transliterations may render the word as "onni." In traditional depictions, oni are powerful demons or ogres with horns, often red or blue skin, shaggy hair, and sharp fangs. They may wear animal skins and wield iron clubs called kanabo. Their abilities commonly include shapeshifting, high strength, and magical powers, and they appear as antagonists in many stories, though some regional legends grant individual oni protective or ambiguous roles.

Role and symbolism in folklore vary by region and era. Oni are frequently associated with disaster, disease, and moral punishment, serving as figures that test or threaten humans. They also function as convenient adversaries in tales that illustrate virtue, resilience, or cleverness. In some narratives, oni inhabit hells or remote mountains, while others place them as wandering tricksters or guardians of thresholds between worlds.

Cultural practices and art have shaped enduring images of oni. The Setsubun festival popularized the ritual of throwing roasted soybeans to drive away oni, accompanied by the cry “Oni wa soto, fuku wa uchi” (Demons out, good fortune in). Oni appear in Noh and Kabuki theater, Ukiyo-e prints, and later in modern media. In contemporary manga, anime, and video games, oni are versatile characters ranging from fearsome antagonists to comic or sympathetic figures, illustrating the broad adaptability of the concept within Japanese culture.

See also: Yokai; Oni in popular culture; Chinese and Buddhist influences. The character 鬼 is the kanji for demon or ogre and underpins the cultural notion of oni in Japanese tradition.