were Japanese monks from Mount Kōya who were sent to preach Buddhism around the country. They were the lowest caste inside the priests' hierarchy of the Mount Kōya temples, and traveled while peddling for a living. They give title to famed writer Izumi Kyōka's most representative short-story.
Former monks who turned to mischief were called Japanese: yadōkai. Moreover, Japanese: kōya hijiri also eventually became a seasonal word (in the context of poetry) for turtles.[1]