In June 1465, the family of bakufu-hoko-shu (servants for bakufu) in the south of Nukata-gun, Mikawa Province and hikan (bureaucrats in lower class) of the Ashikaga clan rose in revolt and built their fortress in a key position of Tokai-do Road, Iguchi (Okazaki City, Aichi Prefecture).
寛正6年（1465年）5月、三河国額田郡南部の幕府奉公衆の一族及び足利氏下級被官層が蜂起し、東海道の要所井口（愛知県岡崎市）に砦を構えた。