The Sumitomo Group (住友グループ) is a group of autonomous Japanese multinational companies.
History
The Sumitomo Group traces its roots to a bookshop in Kyoto founded circa 1590 by Masatomo Sumitomo, a former Buddhist monk.[1] Even today, the corporation is run by his "Founder's Precepts", written in the 17th century.[1]
Copper refining made the company famous. Riemon Soga, Masatomo Sumitomo's brother-in-law, learned Western methods of copper refining. In 1590, he established a smelting business, Izumiya, literally meaning "spring shop".[1] Riemon perfected techniques that allowed the extraction of silver from copper ore, something Japanese technology had not previously accomplished.[1]