Raiko was a legendary archer and hero during the reign of Emperor Murakami, who killed numerous demons during his career (948–1021).
His original name was Minamoto no Yorimitsu, and though of the bushi (warrior) class (that is, not aristocrat in Heian Japan), he was appointed to several governorships.
He was approached in a dream by the daughter of a legendary Chinese archer who declared he was the worthy heir of her father, and who left him a bow and arrows.
With his four companions, including the strong man Kintoki, he cleared the land of demons and monsters. He killed the monstrous Shutendoji, a giant robber who used to feast on human flesh and was a great wine bibber, from whence his name (Chief drunk boy). At night Shutendoji would be transformed into an oni. With his band, Raiko set out to kill the ogre.
Disguising themselves as yamabushi, they carried their weapons and armor in the medicine boxes on their backs. On their way they met a woman who showed them the path to Shutendoji’s castle. The Sumiyoshi kami gave Raiko a drug to make Shutendoji drunk, a magic golden cap, and silken cords. At the castle they asked for shelter for the night.
Shutendoji offered them human flesh, which they pretended to like, and as a consequence, he offered them drink. Raiko offered to make the ogre a potent drink, drugging the wine with the medicine he had received from Sumiyoshi. When the robber had fallen asleep, Shutendoji assumed his real shape as a fanged oni. The band armed themselves, bound the ogre with the silken cords, and then cut off his head. The head jumped up and embedded its fangs into Raiko’s helmet but the golden cap saved his life. The headless but still living demon was hacked to pieces by Raiko’s retainers.
On another occasion, Raiko and his band killed the oni of Mt. Oeyama, who drank human blood instead of wine. In Kaguragaoka they killed the yama uba (mountain ogress) dressed in white, with her breasts falling by her knees. She gave way before them, and they forced their way into the underground palace she was guarding. They were enticed into a cave by the vision of a beautiful woman, only to find themselves enmeshed in the cobwebs the magical giant spider had woven. Raiko prayed for assistance to Shoki the demon-queller, and, thrusting with his sword, dispatched the monster.
He or one of his retainers, Watanabe no Tsuna, dispatched the shapeshifter bandit Kidomaru, who could assume the guise of any animal. They spied him in ambush in the form of a bullock and killed him before he could act.
Falling ill one day, Raiko was sent some medicine. The medicine made his condition worsen, and, suspecting the messenger, he stabbed him with his sword. One of his retainers followed the blood trail and dispatched the giant spider that had disguised itself as a doctor’s assistant.
Joly, Henri L. 1967. Legend in Japanese Art. Tokyo: Charles E. Tuttle Co.
Sato, Hiroaki 1995. Legends of the Samurai. Woodstock, NY: Overlook Press.