Tradition: Japanese mythology
Alternative Names: Tsunodaishi, Horned Daishi, Gansan Daishi
Category: Demon
The Myth
Tsunodaishi is the demon-like form of Ryōgen, the eighteenth head of the Tendai Buddhist sect. He is depicted as a slender, horned, demonic figure and is believed to represent Gansan Daishi after transforming himself into a yaksha.
Ryōgen was a highly revered monk of the Heian period, and many legends and anecdotes developed around him. According to the legend of Tsunodaishi, Ryōgen became seriously ill and made a vow to ward off illness from himself and from other people. He transformed his appearance into that of a terrifying yaksha and saw this demonic form reflected in a mirror.
Ryōgen declared that wherever his image was placed, evil spirits would not enter and calamities would be driven away. His demonic image therefore became a protective charm against evil.
Images of the Great Master were subsequently placed on buildings throughout society, from the pillars of major temple gates to the doors of ordinary people’s thatched houses. The image was intended to protect those places from evil spirits and misfortune.
A similar account appears in the Inōshō, compiled by Gyōyo around the Bun’an era (1444–1449), indicating that images of the Great Master were already regarded as protective charms against evil at that time. However, that earlier account does not mention Ryōgen transforming into a yaksha.
Sources
Takahashi, Toshihiro. “角大師 [つのだいし] (Tsunodaishi).” 新版TYZ 妖怪図鑑 (New TYZ Yokai Encyclopedia). August 25, 2019. https://tyz-yokai.blog.jp/archives/1074589343.html