Since his father Sadaaki died after being involved in the internal conflict between Dosan SAITO and Yorinari TOKI, the governor of Mino Province, he escaped to his maternal grandfather Sadahiro SUGANUMA's place.
天文(元号)21年（1552年）6月、父の定明が美濃守護土岐頼芸と斎藤道三の間の内紛に巻き込まれて死んだため、外祖父・菅沼定広を頼って落ち延びる。