立憲民政党
Taketomi was elected to the lower house of the Diet of Japan in the 1890 General Election. Although defeated in the 1892 General Election, he was reelected in the March 1894 General Election, and served twelve consecutive terms until 1924. He was one of the founders of the Rikken Kaishintō in 1894. Over the course of his career, he moved from the Shimpotō, Kenseitō, Kensei Hontō, Rikken Kokumintō, Rikken Dōshikai, Kenseikai and finally Rikken Minseitō.