During your travels in Japan, you might have heard about oni, the demons or ogres of Japanese folklore. These mythological monsters are typically portrayed as menacing savages with horns and sharp fangs, but can also take on a gentler, more endearing persona, even appearing in children’s games. With the international release of the hit Japanese anime Demon Slayer, there’s now growing interest in oni from abroad.
What you may not know is that Kyoto has its own oni stomping ground. The Oeyama area in the northern part of the prefecture is oni country abounding with ancient oni folklore and a host of opportunities to be charmed by these devilish creatures.
Before venturing out to Oeyama, let’s take a look at how oni figure in the Japanese imagination. According to Hideki Sato, head of Japan Oni Cultural Museum in Oeyama, the term “oni” is thought to originate from an old word meaning “unseeable presence”. In ancient times when people were constantly at the mercy of nature and plagues, they feared supernatural powers, and attributed misery and misfortune to invisible, malevolent spirits. Oni as we understand them now evolved from this idea.
The popular reputation of Japanese oni as purely evil beings is, however, overly simplistic. In reality, they are much more diverse in nature. Mr. Sato explains that in the Middle Ages it was thought that oni were mortals that had been transformed as the result of overwhelming anger or sorrow. Due to their formidable strength, oni often take on a role of guardian deity that protects humans from evil, and as such play a central part in many festivals and religious rituals in Japan. The Japanese language is peppered with references to oni: the children’s game tag is called oni-gokko (literally, “playing at oni”); and there are numerous oni-related idioms—a Japanese speaker may mention “giving the oni a gold rod” (giving someone or something a decisive advantage) or “making one’s heart an oni” (hardening one’s heart), for example. Oni are inextricably linked to Japanese life, culture, and customs.
Oeyama’s Oni Lore
A depiction of Oeyama’s most famous oni, Shutendoji (courtesy of Japan Oni Cultural Museum and Fukuchiyama City Board of Education)
Oeyama is a mountain range that extends across four municipalities in northern Kyoto Prefecture. It’s Kyoto’s most popular mountain destination, boasting a rich natural environment of largely unspoiled forestland, and historically was the location of a major traffic route. There are three famous oni legends associated with Oeyama.
1. Shutendoji Slaying
Thought to date back to around the 14th century, this is the most famous of Oeyama’s oni tales and has been made into various Noh and kabuki plays. In 10th century Kyoto, an oni by the name of Shutendoji was abducting princesses from the city and imprisoning them in his lair deep in the mountains of Oeyama. The emperor dispatched a band of oni-busters led by a samurai named Raiko to slay Shutendoji. They tricked him into drinking poisoned sake and beheaded him. The giant Shutendoji is purported to have been fifteen meters tall with five horns and fifteen eyes.
2. The story of Hikoimasu-no-kimi
Over two thousand years ago during the reign of Emperor Sujin, the emperor’s younger brother, Hikoimasu-no-kimi, was ordered to kill a giant demon spider called Kugamimi-no-mikasa. They fought near the Yura River, and the spider ran away to Oeyama. This is thought to be the oldest Oeyama oni legend.
3. The story of Prince Maroko
In the late 6th century, a trio of oni were terrorizing the people of Oeyama. Prince Maroko was sent by the emperor to subjugate the oni and successfully defeated them. This legend has given birth to some seventy place names, temples, and shrines in the Oeyama area.
So why has Oeyama spurred so many oni legends?
Well, it’s difficult to give a definitive answer because there are several theories. Geographically, Oeyama was a frontier between two provinces. Being remote and sparsely populated, it had a reputation as a lurking-ground for bandits and other suspicious characters. There was also a mine in the area, and Oni legends are common in mining communities across Japan—it’s not hard to imagine that brawny men working among red-hot flames might have looked like oni. Another theory is that indigenous residents subjugated by a more powerful regime wove their experiences into oni-slaying stories. The folks here don’t necessarily empathize with the heroes of the stories, but often with the so-called villains. Every oni that is slayed has its own story too; they’re just not told.
