Buaku (demon mask): a caricature of the O-Beshimi mask used for Tengu (mountain goblins) in Noh. The Kyôgen Buaku mask indicates a character who is only outwardly powerful; inside he is actually quite timid, with a maudlin streak to him (as indicated by the sorrowful eyes). Used for King Emma (the ruler of Hell), the Thunder God, and for the largest "demon" mushroom in Kusabira (Mushrooms). From this variety of uses we can guess that in the Muromachi period the category of minor deities has become indistinguishable from the category of demons, especially when they are objects of humor.