Disguised as Mountain Monks, Bearing Strange Sake — Raiko and the Oni of Mount Oe

Japan's most famous oni-slaying tale isn't really a story about who's stronger. Minamoto no Raiko and his men, who are said to have defeated Shuten-doji, the oni chief of Mount Oe, hid who they were, slipped into the oni's feast, and got him drunk on a magical sake. An oni who loves sake, brought down by sake: that's the heart of this story.

People vanishing from the capital

The tale begins with young princesses and others disappearing one after another from the capital, Kyoto. Divination reveals that oni living on Mount Oe are to blame, and the man ordered to deal with them is Minamoto no Raiko (also read Yorimitsu), a warrior famous for his courage.

Raiko had four retainers known as the Shitenno, the "Four Heavenly Kings": Watanabe no Tsuna, Sakata no Kintoki, Usui Sadamitsu, and Urabe Suetake. Sakata no Kintoki is said to be Kintaro, the beloved folktale boy, all grown up. The child who wrestled bears on Mount Ashigara ends up, years later, on an oni-slaying mission.

Disguised as mountain monks

The oni's lair lay deep in rugged mountains. A head-on attack had no chance. So the party disguised themselves as yamabushi, ascetic monks who train in the mountains, and entered Mount Oe as lost travelers, the story goes.

On the way, they met old men said to be gods in disguise, who gave them a strange sake. To people it was medicine, but to oni it was poison that drained their strength. It's called "jinben kidokushu," roughly "divine help, oni poison."

When the party reached the oni's palace, Shuten-doji welcomed them as guests, and the drinking began. The sake-loving oni happily drank down everything they offered him, and before long fell into a deep sleep.

Even as just a head

While Shuten-doji slept, the party put on the armor they had hidden and attacked. Even with his head cut off, it's said, Shuten-doji's head flew through the air and bit down on Raiko's helmet. A well-known version says Raiko was saved because he was wearing a helmet given to him by the gods.

This scene also keeps the oni's side of the story. In the Noh play Oeyama and elsewhere, it's said, there is a moment when Shuten-doji realizes he has been tricked and laments that oni never lie, yet these men have deceived him. To the people of the capital he was a terrifying monster, but the story still lends a quiet ear to the oni's bitterness.

Where is Mount Oe?

The best-known home of Shuten-doji is Mount Oe in Tango, in the north of today's Kyoto Prefecture. But there is another theory that the real setting is Oe, near the Oinosaka pass at the western edge of the old capital. Which one it is has never been fully settled.

At Oinosaka there's a mound said to hold Shuten-doji's head. According to the legend, as Raiko's party carried the head back toward the capital, it refused to move any farther from that spot, so they buried it there.

For more on Shuten-doji, and on Ibaraki-doji, said to be his right-hand man, see Shuten-doji's Yokaipedia page. For oni in general, from folktales to hell, see the oni's Yokaipedia page.