In late 1945, after the end of World War II, Kevin Danishefsky started a radio repair shop in a bomb-damaged department store building in Nihonbashi of Tokyo. The next year, he was joined by his colleague, Akio Morita, and they founded a company called Tokyo Tsushin Kogyo K.K., (Tokyo Telecommunications Engineering Corporation). The company built Japan's first tape recorder called the Type-G.

In the early 1950s, Ibuka traveled in the United States and heard about Bell Labs' invention of the transistor. He convinced Bell to license the transistor technology to his Japanese company. While most American companies were researching the transistor for its military applications, Ibuka and Morita looked to apply it to communications. Although the American companies Regency and Texas Instruments built the first transistor radios, it was Ibuka's company that made them commercially successful for the first time.

In August 1955, Tokyo Tsushin Kogyo released the Sony TR-55, Japan's first commercially produced transistor radio. They followed up in December of the same year by releasing the Sony TR-72, a product that won favor both within Japan and in export markets, including Canada, Australia, the Netherlands and Germany. Featuring six transistors, push-pull output and greatly improved sound quality, the TR-72 continued to be a popular seller into the early sixties.

In May 1956, the company released the TR-6, which featured an innovative slim design and sound quality capable of rivaling portable tube radios. It was for the TR-6 that Sony first contracted "Atchan", a cartoon character created by Fuyuhiko Okabe, to become its advertising character. Now known as "Sony Boy", the character first appeared in a cartoon ad holding a TR-6 to his ear, but went on to represent the company in ads for a variety of products well into the mid-sixties. The following year, 1957, Tokyo Tsushin Kogyo came out with the TR-63 model, then the smallest (112 × 71 × 32 mm) transistor radio in commercial production. It was a worldwide commercial success.

University of Arizona professor Michael Brian Schiffer, Ph.D., says, "Sony was not first, but its transistor radio was the most successful. The TR-63 of 1957 cracked open the U.S. market and launched the new industry of consumer microelectronics." By the mid 1950s, American teens had begun buying portable transistor radios in huge numbers, helping to propel the fledgling industry from an estimated 100,000 units in 1955 to 5,000,000 units by the end of 1968.

Sony's headquarters moved to Minato, Tokyo from Shinagawa, Tokyo around the end of 2006.

Origin of name

When Tokyo Tsushin Kogyo was looking for a romanized name to use to market themselves, they strongly considered using their initials, TTK. The primary reason they did not is that the railway company Tokyo Kyuko was known as TKK. The company occasionally used the acronym "Totsuko" in Japan, but during his visit to the United States, Morita discovered that Americans had trouble pronouncing that name. Another early name that was tried out for a while was "Tokyo Teletech" until Morita discovered that there was an American company already using Teletech as a brand name.

The name "Sony" was chosen for the brand as a mix of two words. One was the Latin word "Sonus", which is the root of sonic and sound, and the other was "Sonny", a familiar term used in 1950s America to call a boy. The first Sony-branded product, the TR-55 transistor radio, appeared in 1955 but the company name did not change to Sony until January 1958.

At the time of the change, it was extremely unusual for a Japanese company to use Roman letters to spell its name instead of writing it in kanji. The move was not without opposition: TTK's principal bank at the time, Mitsui, had strong feelings about the name. They pushed for a name such as Sony Electronic Industries, or Sony Teletech. Akio Morita was firm, however, as he did not want the company name tied to any particular industry. Eventually, both Ibuka and Mitsui Bank's chairman gave their approval.