In 1918, Ōkōchi studied watercolor under Sanchi Itakura and printmaking under Kishio Koizumi as well as other methods under Okada Saburōsuke.
He contributed to the magazine You and I (きみ と ぼく, Kimi to boku) in 1922.
He graduated from the Meiji University Department of Economics in 1928 and studied at Hongō Painting Institute under Manjirō Terauchi in 1930.
Ōkōchi participated in the 1931 Nihon Hanga Kyōkai exhibition.
[1] In 1933, Ōkōchi's painting, A corner of the room (画室の一隅, Gashitsu no ichigū), won the fourteenth Emperor Exhibition prize from the Imperial Art Academy.