Studied in Germany till 1927.
After studying in Germany, he became a professor at his alma mater (1927). He was a director of Nihon University and director of the Osaka College before he became president of Kinki University.
Koichi Seko was active as a member of the Hoarded Goods Inquiry Committee of the Lower House in early postwar years.
He was elected to the House of representatives seven times (since 1932). Belonged to the Seiyukai Party before the war and became a member of Liberal-Democratic Party.