Mitsui (三井) is one of the largest corporation groups in Japan.
Founded by Takatoshi Mitsui (1622-1694), who was born a second son of a shop in Matsuzaka, called Echigoya (越後屋) in today's Mie prefecture. The shop was oroginally selling miso, liquor along side with pornshop. Later, the shop built a branch in Edo (today's Tokyo).
He moved to Tokyo when he was 14 years old followed his older brother. Since he was very young, he had shown outstanding business talent. But because of that, his brother sent him back to Mie when he was 28 years old. He waited for 24 years until his older brother passed away. He took over Echigoya and opened the new branch as large Gofukuya (means Kimono shop) at Nihon-Bashi, the heart of Tokyo, in 1673. Later the Gofukuya devision separated from Mitsui, and called Mitsukoshi.
Traditionally, Gofukuya's business style was Order Made style; visit the customer's house (Normally high social class or rich business people), take order, then create products. The accountancy was Margin transaction. But Mitsui started producing products first, and then sold at the shop exchange with cash. It was new method in those days' Japanese market.
In 1683, Takatoshi opened exchange shop in Tokyo and soon it became Edo government's Purveyor. At the time, Edo government had business deal at Osaka, selling tax crops or other material for land tax, and then sent money to Tokyo. But money transportation was always risky, so the exchange shop substitutes payment.
In July 1, 1876, first Japanese Private bank, Mitsui bank (today's Mitsui Sumitomo bank was started. Its president was Takashi Masuda (1848-1938)
See also: List of Japanese companies