The komusō also adopted their distinctive woven wicker hat or mask, called a tengai, that looks like an overturned basket with slits for the monks to see out of. Wearing one traditionally symbolized a dismissal of ego or self, though the masks also hid the identity of the wearer
Many of the komusō were ronin, or wandering samurai, looking to start a new life with the anonymity the attire provided.
More…here
Additional info can be found Wikipedia