The underlying cause of the fighting was due to the powerful Matsuda clan and others (who had served as military governors of Bizen Province early in the Muromachi Period) trying to grasp control of Bizen Province from the Akamatsu and Uragami clans.
これは室町初期には備前守護に任じられたこともある有力国人の松田氏らが、赤松・浦上氏の備前支配を排除しようとしたことが遠因になったとされる。