The idea of “sennin” in Japanese mythology derived from the teaching of Taoism in China. A sennin is a hermit, who has acquired immortality and supernatural power by his asceticism in the mountain. The Ikkaku Sennin mask represents the one-horned hermit, born from a female deer and has the very strong supernatural power. It is used for the play “Ikkaku Sennin.”

In the play, Ikkaku Sennin, who lives in the mountain in India, battled with the thunder god and he has imprisoned the thunder god so that no rain will fall. Being troubled with this, the emperor sends for beautiful women to entertain Ikkaku Sennin with sake and dance. Drunken with sake and fascinated by the seductive dancing, he loses his power and the rain god escapes to save the crops.

The mask is used as Ayakashi and Shinkaku when a horn is removed.