The komusō (虚無僧, komusō, hiragana: こむそう; also romanized komusou or komuso) were a group of Japanese mendicant monks of the Fuke school of Zen Buddhism who flourished during the Edo period of 1600–1868.
The order went underground following reforms introduced by the post-Edo government. The last adherent disappeared mysteriously in the 1950s, since when nothing has been heard of the order.
Komusō were characterized by a straw bascinet (a sedge or reed hood named a tengai) worn on the head, manifesting the absence of specific ego but also used for being able to travel incognito.
It was very rare to catch sight of a Komusō with his mask removed.