A main character of 'The Blue Hood' is a Zen master Kaian, also known as Kaian Myokei, who really existed and is known for establishing Daichu-ji Temple in Shimotsuke Province.
「青頭巾」に出てくる主人公の改庵禅師は改庵妙慶といって、下野国大中寺を創建したことで知られる実在する僧侶である。