Oni (a term often translated as "demon" or "ogre" in English) are part of Japanese culture as beings both feared and marginalized. Oni occupy a deeply rooted and multi-layered place in Japan's cultural and historical imagination. While today they are commonly portrayed in popular culture as large, horned, red or blue-skinned monsters wielding metal clubs, oni have not only functioned as supernatural creatures throughout history but have also symbolized social exclusion, the concept of the "other," and objects of fear.

^{Oni Kabuki Mask (Flickr)}

Origins and Mythological Development

The concept of oni traces its origins to the Chinese notion of gui (鬼), rooted in ancient religious and philosophical traditions. In China, gui referred to spirits or ghosts believed to exist in the realm of the dead—sometimes malevolent, sometimes protective. From the 7th century onward, this concept was transmitted to Japan, where it evolved through partial transformation and integration with local beliefs into the form now known as oni. In Japanese culture, the term came to signify primarily malevolent, fearsome, and dangerous entities.

The earliest official historical texts, such as the Nihon Shoki (720), along with other Heian-period documents, suggest that oni were regarded as real beings with a tangible impact on daily life. During the Heian period, for instance, people would carefully choose days and directions for outings to avoid encounters with oni said to appear at night. Reports from the late 9th century in Kyoto even claimed that a woman had been devoured by an oni.

From the 12th century onward, depictions of oni in early texts and artworks began to standardize: they were shown as horned creatures, red or blue in color, and sometimes with horse or ox heads. These visual representations were influenced by Buddhist teachings, particularly the concepts of greedy spirits (gaki) and guardian spirits (yaksha). However, the common image of oni wielding iron clubs dates to the Edo period (1603–1868).

Oni and Social Exclusion

Beyond their role as supernatural beings, oni have also come to symbolize marginalized and “other” groups within Japanese society. Infants born with physical differences were historically labeled as onigo (“oni children”) and often abandoned. During the spread of Buddhism, women and people with disabilities were frequently stigmatized and depicted through the imagery of female oni, reinforcing their social exclusion.

Women, in particular, were increasingly associated with negative traits such as jealousy and sexuality following the rise of patriarchal structures from the 9th century onward. As a result, theatrical traditions such as Nō frequently featured oni characters portrayed as jealous or deranged women. The paradox of women being both socially excluded and symbolically central as sources of life positioned them as beings both feared and in need of control.

Additionally, groups perceived as culturally or ethnically different—such as foreigners—or socially peripheral figures, including elderly women living in rural or mountainous regions (yamauba), were also associated with the oni archetype. Yamauba, often portrayed as old women exiled to the forests, later evolved into exotic and sexually charged figures in Kabuki theatre and ukiyo-e prints. The urban legend of kuchisake-onna (“the slit-mouthed woman”), which spread in Japan in 1979, can be seen as a modern adaptation of these older motifs.

Use Through War and Politics

Throughout history, the concept of oni has been employed as a tool for demonizing enemies and unifying the populace. During the Russo-Japanese War, Russian soldiers were likened to oni, and in World War II, this symbolism was extended to portray American and British troops in the same light. Such propaganda was effective in generating fear and anger toward the enemy within Japanese society.

In Japan’s first full-length animated feature film, Momotarō: Umi no Shinpei (Momotarō: Sacred Sailors, 1945), enemy forces are depicted as single-horned oni, reinforcing the association between monstrous figures and wartime adversaries.

Oni in the Modern Era

With the advent of industrialization, secularization, and the rise of mass media, oni have shifted from objects of collective fear to figures of entertainment. In books, comics, and television, oni are now portrayed as reflections of human psychology—sometimes sympathetic, sometimes frightening. These modern oni characters differ significantly from the terrifying monsters of folklore, often appearing as complex, multi-dimensional figures in popular series.

Furthermore, the oni figure has been repurposed in Japan as an economic and cultural asset through tourism and revitalization projects. For instance, oni museums have been established in towns such as Ōe-machi in Kyoto and Kitakami in Iwate Prefecture. In these communities, oni are reinterpreted as ancestral guardians and deities of good fortune. As a result, the cultural legacy of oni is preserved while simultaneously contributing to regional development.

^{An Oni Figure (Flickr)}

The Ever-Changing Identity and Significance of Oni

Throughout history, oni have been fluid figures—perceived both as terrifying and sacred, embodying social exclusion and the experience of being “other.” They occupy a profound place in the collective psyche of Japanese society as symbols of both supernatural beings and marginalized individuals. Their dual nature, embodying both malevolent and benevolent qualities, has been utilized over time to maintain social order, evoke fear, and shape collective identity and belonging.

In conclusion, the oni figure is an indispensable key to understanding the complex layers of Japan’s cultural history and social structure. They should not be seen merely as mythological monsters but as reflections of human nature, societal fears, processes of marginalization, and historical dynamics.