[37] Itochu started in 1858, shortly after the opening of Japan to foreign trade, when Chubei Itoh (伊藤 忠兵衛, Itō Chūbei) began door-to-door wholesaling of linen in the regions between Osaka and Kyushu.

Itoh's company grew considerably in the wake of World War I, with offices in the United States, India, the Philippines and China, and the firm began to handle machinery, automobiles and metals in addition to its core business of textiles.

However, a recession in 1920 left the company deeply in debt, and unlike the major zaibatsu firms of the time, it had no captive bank to finance its business.

In 1947, in accordance with the Law for Elimination of Excessive Concentration of Economic Power, Daiken Co., Ltd. decided on a corporate restructuring plan centered on the separation of the manufacturing and trading divisions.

[1] Daiken Co., Ltd., a company created from the merger of trading and manufacturing firms during World War II, separates into C. Itoh & Co., Ltd., Kureha Cotton Spinning Co., Ltd., Marubeni Co., Ltd., and Amagasaki Nail Works, Ltd.

The inflation that had continued since the end of the war was brought under control by the Dodge Line, and from around 1949, Japan accelerated its progress toward a liberal economic system.

The new Itochu established its head office at 2-36 Honmachi, Higashi-ku, Osaka, and began domestic sales and import/export operations in the three fields of textiles, machinery, and general goods.

Since 1950, The Korean War gave further impetus to the Japanese economy, and ITOCHU greatly improved its performance in import and export transactions.

Starting out as a textile trading company, it expanded its business in non-textile fields such as aircraft, automobiles, petroleum, and machinery, and accelerated its progress towards generalization.

In March 1950, the company concluded a general sales agency agreement with Roots, a British automobile manufacturer, and it established an aircraft section to respond to the resumption of civil aviation.

After the first oil-price shock struck Japan (1973 oil crisis), the country's economy has entered a steady increasing stage till 1990'.

Soon after this appointment, on September 29, 1972, Japanese Prime Minister Kakuei Tanaka achieved a normalization of diplomatic relations between Japan and China.

[40] Former Imperial Japanese Army staff officer Ryuzo Sejima joined Itoh in 1958 after spending 11 years in a Siberian prison.

Four years later, he was promoted to director and became Itoh's head of corporate planning, implementing a military-style internal reporting system.

In 1970, Sejima and his younger protege Minoru Murofushi arranged a joint venture between General Motors and Isuzu, one of the first tie-ups between US and Japanese automakers.

[41] In 1971, the company successfully assisted in arranging a basic contract for cooperation between General Motors of the United States and Isuzu of Japan.

The first investment of GM taking a 34% stake in Isuzu was seen in 1972, when the Chevrolet LUV became the first Isuzu-built vehicle to be sold in the United States.

While the company had a long relationship with GM going back to the 1920s, Isuzu introduced the Gemini in 1974 which was co-produced with General Motors as the T-body Chevrolet Chevette.

Ataka had recently suffered major losses from an oil development project in the United States and had undergone restructuring at the direction of its main lender, Sumitomo Bank.

Itochu began to develop a strong information technology business in the 1980s through its subsidiary C. Itoh Techno-Science (CTC), which acted as a Japan distributor for Sun Microsystems, Cisco, Oracle and others.

[41] After the economic miracle and consequent asset price bubble the country experienced a recession period the lost decade.

Trying to deflate speculation and keep inflation in check, the Bank of Japan sharply raised inter-bank lending rates in late 1989.

[45] By the early 1990s Itochu had become the largest trading company in Japan, but losses from the Japanese asset price bubble, particularly domestic real estate investments, brought it down to third place by the middle of the decade.

At the period, both ITOCHU and Marubeni have been experiencing excessive competition in the domestic market of steel and metal products and the two entities who share the same history routes filed the dialogues towards merging the similar operations into MISI.

In March 2016, Itochu recorded JPY 352.2 bil in PAT in the fiscal year which ranked itself as the most profitable sogo shosha for its first time.

The natural resources commodity price was decreased during the fiscal year ended in March 2016, which made its competitors Mitsubishi Corporation and Mitsui & Co Ltd fell in profits.

[53][54] In July 2016, an American short seller Glaucus Research Group published a report critical of Itochu's accounting practices, causing a stock price dip of around 10%.

[57] In September 2020, Warren Buffett's Berkshire Hathaway announced that it had acquired over 5% of the stock in the company, along with four other Japanese trading houses, over the 12-month period ending in August 2020.