Yamato Gokin was established in 1941 as a special metals laboratory in Itabashi-ku, Tokyo, Japan. Its founder and president, Dr. Shigeru Hagino, started this company for research and development as well as for manufacturing high-strength and fine-grain alloys (YG bronze) to meet assorted requirements in vital machine parts for various industries such as automobiles, aircraft, and shipbuilding. These alloys became known for their high quality and superior performance, and consumer demand increased rapidly.

This laboratory was reorganized into Yamato Gokin (Alloy) Ltd. in April, 1943, for production of mostly government supplies. Machine parts made from these special, strong alloys were were supplied to the Army, Navy and Air Force with remarkable results.