What are komuso?

"Komuso" monks (written "monks of nothingness") were mendicant monks in ancient Japan who used the shakuhachi as a religious tool. Specifically, they belonged to the Fuke sect of Zen Buddhism. Komuso monks were itinerant, wandering the country and begging for alms as they played shakuhachi honkyoku. They wore a straw basket (called a "tengai") that covered their head as they played. Because some of these komuso were in fact spies for the government, when there was a revolution in 1868, the entire Fuke sect was dismantled and the playing of shakuhachi temporarily banned, leading to a great loss of shakuhachi information and lore.
Following is an excerpt from materials collected for the "Mejiro 2002 Komuso Exhibition" by Kayu Kanda:
'The precursors to komuso were the "komoso", which is written "straw mat monks", who emerged in the late 15th century. These monks played shakuhachi as they traveled throughout various lands, and they used straw mats which they carried about their waists to sleep outdoors. This is how they got their name. In the beginning of the Edo period they started the tradition of wearing the "tengai", or straw baskets on their heads and became "komuso", or "monks of nothingness". Instead of the traditional spiritual practice of chanting sutras, the komuso used their shakuhachi to play honkyoku as a spiritual practice.
'There are many legends surrounding the origin of the shakuhachi and the komuso. One legend gives credit to a monk named Hotto-Kokushi (also called Kakushin) (1207-1298), who studied at the Sung court in China for 6 years and then returned to Japan with 4 practitioners, while another legend gives credit to a monk named Roan who lived in Uji in Japan.
The komuso monks formed into the Fuke sect of Zen Buddhism around the year 1700, but they remained a poor sect because they lacked the financial backing of patrons that the other sects enjoyed. The sect was outlawed in 1872.'