It is said that the precepts of the Mito family stated "the Mito family shall follow the Emperor without hesitation if a war ever starts between the soke (the head family) of the Tokugawa clan and the Imperial Court."
「もし徳川宗家と朝廷との間に戦が起きたならば躊躇うことなく帝を奉ぜよ」といった家伝あった。