Masao Okaya graduated from Tokyo University (1936).
Masao Okaya served first with Nihon Kokan Kaisha (Steel Pipe Company) and then as director of Okaya Shoji Kaisha (Trading Company) and a few other companies. He became president of Okaya Koki Kaisha and director of Nagoya Chamber of Commerce & Industry (1945). Held executive posts with several other companies including that of director of Sogo Building Company. Holds additional posts of chairman of Aichi Prefectural League of Japan Boy Scouts, director of Nagoya Television Corporation, director of Nagoya Rotary Club and auditor of Mainichi Kaikan (Mainichi Hall).