 He accepted a post as a prosecutor at the Ministry of Justice from April 1873 and was promoted steadily until he reached the position of chief prosecutor at the Tokyo District Court in May 1877.However, the following month, in response to the Satsuma Rebellion, he joined the Imperial Japanese Army and was given the rank of major.He served as chief-of-staff of the "Shinsenryodan," a unit composed of former Kuwana samurai and members of the "Shinsengumi."