It originated from the hostility between the Toyota clan, monk-soldiers of Kofuku-ji Temple Daijo-in, and the Ido clan, monk-soldiers of Kofuku-ji Temple Ichijo-in, and spread to the whole Yamato Province.
興福寺大乗院衆徒の豊田氏と興福寺一乗院衆徒の井戸氏の対立に端を発し、大和一国に広がった。