Iron Sōmen in the Shape of a Tengu, Full-face Mask, Edo Period

A mask that covers the entire face, known as sōmen, is a dramatic feature of Japanese armour of the Edo period (1603-1868). Simple armoured masks, usually protecting only part of the face, had been developed for practical use during the more violent Muromachi period (1333–1573). However, during the peaceful Edo period when demand for more ceremonial armour has high, craftsmen had more freedom to explore their imagination, as they did when making representational helmets, and created masks in forms ranging from fierce gods to comical folk characters.

Tengu are mythical creatures that live in the mountains in Japanese folkore. The legend originated from China from around the 6th to 7th century. They were regarded as mischievous, half tobi (type of hawk) and half human. Because of their dual nature, they were able to fly and transform into human figures. Although Buddhism treated Tengu as evil beings, their image has improved somewhat in more recent times. The Tengu became particularly popular subjects during the eighteenth century during which more virtuous Tengu started to appear in stories and were linked to the yamabushi tradition of mountain asceticism.