Onryou (meaning “vengeful spirit”) masks are used to portray characters
who died a regrettable death in battle or a woman who died mad with jealousy
and returns from the nether world to haunt the person who is the target of her ill will.
It expresses its supernatural existence by fixing the eyes with
gold crowns and gold paint (gold dust mixed with glue) the same way Kishin and Shinrei masks do.