What is a Hannya mask?

Hannya masks are used in Japanese noh and kyogen plays as well as in kagura dances. They are meant to represent serpents or female demons.

When seen head-on, the mask resembles a devil or demon with horns, stringy hair and a wide smile. It is designed to look sorrowful when the head is tilted down, however. Characters who don the mask in plays and dances are generally women who have become possessed by demons due to their jealousy or obsessive behavior. The color of the mask is also significant. White represents an aristocratic woman, red represents a lower-class woman and dark red represents the demon that has possessed the woman.