After his father's death he was brought up by Nakatsukasajo OWARI, but backed up as a Daishogun (command-in-chief) by Chikahira IZUMI, Gozoku (local ruling family) of the Shinano Province (the present Nagano Prefecture) who had antipathy toward the Hojo clan, and forced a conspiracy to assassinate Yoshitoki HOJO, when the conspiracy was exposed in March, 1213, he was arrested by the Hojo clan (Chikahira IZUMI War).
父の死後、尾張中務丞によって養育されていたが、北条氏に反感を持つ信濃国（現在の長野県）の豪族泉親衡に大将軍として擁立されて北条義時誅殺の陰謀に加担させられるが、建保元年（1213年）2月にこれが露見して北条氏によって捕縛された（泉親衡の乱）。