I came up with this when researching different Yokai in Japanese folklore. Noderabo (field temple priest) stood out and I decided to create a version that was grounded in reality and would explain the supernatural element.
Rather than a demon ringing the bell at a dilapidated Temple, a ronin decided to take residence at a temple, and when unwelcome visitors would arrive, he would deal with them appropriately. Through word of mouth, the tales of 'Noderabo' spread. To take advantage of the myth, the Ronin adopted the attire to continue the sharade until he decided to move on to his next destination.
~Part of my 1 Character per week Goal~