Koichiro Samukawa graduated from Metallurgy Department of Tokyo University (1929).
Koichiro Samukawa entered Furukawa Denki Kogyo Kaisha (Furukawa Electrical Industry Company). Transferred to Tokai Electric Manufacturing Company (1935) and later became director of the company and of Tokyo Kokyu Imono Kaisha (Tokyo High-Class Cast Metal Company).
He made inspection tour of Europe and America. He served also as auditor of Nihon Pitch Cokes Industry Company and director of Toyo Hamono Kaisha (Toyo Cutlery Manufacturing Company) and Nihon Kijuki Seisakujo (Japan Crane Manufacturing) Company, director of Motor Plant of Dengyosha (Electric Industry Company) and chief director of Nihon Tanso Kogyo Toseikai (Japan Carbon Industry Control Company). President of Tokai Denkyoku Seizo Kaisha (Тoкаі Electrode Manufacturing Company) (since 1941) and Tokai Konetsu Kogyo Kaisha (Tokai High Temperature Industry Company) (since 1945).