As he expected, the change of his family name earned Itagaki the tremendous support from Kai people, leading to his landslide victory at the Battle of Koshu-Katsunuma.
この改姓の後、退助の目論見どおり甲斐国の民衆に絶大な支持を受け、甲州勝沼の戦いで大勝をした。