Mitsui & Co., also known as Mitsui Bussan, is one of the largest sogo shosha in Japan, and also part of the Mitsui Group. Its business area covers energy, machinery, chemicals, food, textile, logistics, finance, and more.

First established in 1876 with 16 members including the founder Takashi Masuda. As Japan's international trading was dominated by foreigners since the end of Edo period, it aimed to get trading right back to Japanese nationals by expanding business by Japanese. By the end of the World War II, it became a dominant trading giant, but was dissolved by the order of GHQ. In 1947, Tatsuzo Minakami, one of the former employees of Mitsui, decided to re-establish the company. Later, as international trading led Japan's economic recovery and growth, Mitsui also enlarged its business area and started various overseas investments, which constitute its current main business.