Son of Shiroemon Tachihara, a samurai of the Hiroshima clan. He was adopted later by Hanai-ke (family of Hanai). He graduated from Igirisu Horitsu Gakko (the English Law School current Chuo University) in 1888. He passed the bar examination in 1890 and started his career as a lawyer. He attracted attention by defending criminal cases such as the High Treason Incident and the Siemens scandal. He was elected a member of the House of Representatives in the 6th general election of 1898. He was consecutively elected until the 13th general election except the 8th. He was instrumental in the implementation of universal suffrage and political innovation. He served as the vice-chairman of the House of Representatives in 1915 and was selected as a member of the House of Peers by Imperial command in 1922. During this period, he became a doctor of law. He served as the president of the Tokyo Bar Association and was appointed as member of various legal Research Commission including the Legislative Council of the Ministry of Justice.