立憲民政党
Ogawa then entered politics, winning a seat in the House of Representatives of Japan in the 1917 general election, and was subsequently re-elected to the same seat in the Okayama constituency a total of eight times. Initially with the "Shinseikai," he later assisted in the formation of the "Seiyu Hontō" political party, subsequently serving as president of its policy research committee, and joined the "Rikken Minseitō" when the "Seiyu Hontō" merged with the "Kenseikai".