The reason why this internal war was also called 'The Utsuro War,' was because those who participated, the vassals of the Date clan as well as the Ashina, Mogami and Soma clans, who were generally regarded as independent Sengoku daimyo, were members of Date's Utsuro at the time of the war.
この乱を「洞の乱」とも呼ぶのはこの内乱に参加した伊達氏家臣は勿論、一般には外部の戦国大名と認識されている蘆名氏や最上氏・相馬氏などもこの乱の当時においては洞の一員であったからである。