After winning the Battle of Koshu-Katsunuma, it was said that Itagaki confronted the portrait of Nobukata ITAGAKI housed in Erin-ji Temple, the family temple of the Takeda family in Kai Province, and was so overwhelmed that he directly wrote down "Our Father" on it.
甲州勝沼の戦いの後、甲斐国の武田氏一族の菩提寺である恵林寺に所蔵されていた板垣信方の肖像画に対面し、感激した退助は直筆で「わが祖」と書き入れたという。