In addition, based on facts that his birthplace Iga is famous for ninja (professional spy in feudal Japan highly trained in stealth and secrecy) and that he walked extremely fast for a Japanese person at that time, there is a theory that he was a ninja outside of the mainstream.
また、出生地伊賀との関係、当時の日本人としては異常な速さの歩き方などから忍者ではなかったかという在野の説もある。