Teikyu Okamoto graduated from Keio Gijuku, predecessor of Keio University (1874) and served in the prefectural offices of Kumamoto and Gumma.
Teikyu Okamoto resigned from public service (1880) and established the Kojunsha Society in Tokyo. Helped found the Jiji Shimpo newspaper and became the head of its printing bureau. Became manager of the Teikoku Marine Insurance Company (1882). Inspected Chinese markets for Japanese cotton yarn (1903) and subsequently held executive posts in the Chiyoda Life Insurance, Toyo Printing and Kanegafuchi Spinning companies.