立憲民政党
Sakurauchi was elected to the Lower House of the Diet of Japan in the 1920 General Election, under the "Rikken Seiyūkai" banner, and was reelected for six terms. Sakurauchi became president of Ibiden company in 1925. He subsequently changed his political party affiliation to the "Rikken Minseitō," and served as Secretary-General of the party in 1927.