She was born as the second daughter of Kazuma YOKOTA from Matsushiro clan in Matsushiro-cho, Hanishina-gun, Nagano Prefecture (present Matsushiro Town, Nagano City [Matsushiro, Nagano Prefecture]).
長野県埴科郡松代町（現・長野市松代町(長野県)松代）に松代藩横田数馬の次女として生まれる。