In addition to the Mainichi Shimbun, which is printed twice a day in several local editions, Mainichi also operates an English language news website called The Mainichi (previously Mainichi Daily News), and publishes a bilingual news magazine, Mainichi Weekly. It also publishes paperbacks, books and other magazines, including a weekly news magazine, Sunday Mainichi.
The history of the Mainichi Shimbun began with the founding of two papers during the Meiji period. The Tokyo Nichi Nichi Shimbun was founded first, in 1872. The Mainichi claims that it is the oldest existing Japanese daily newspaper with its 136-year history. The Osaka Mainichi Shimbun was founded four years later, in 1876. The two papers merged in 1911, but the two companies continued to print their newspapers independently until 1943, when both editions were placed under a Mainichi Shimbun masthead. In 1966, the Tokyo office was moved from Yurakucho to Takebashi, and in 1992, the Osaka office was moved from Dojima to Nishi-Umeda.
The Mainichi has 3,200 employees working in 364 offices in Japan and 26 bureaus overseas. It is one of Japan's three largest newspapers in terms of circulation and number of employees, and has 79 associated companies, including Tokyo Broadcasting System (TBS), Mainichi Broadcasting System (MBS) and the Sports Nippon Newspaper.
The Mainichi is the only Japanese newspaper company to have won a Pulitzer Prize. The Japan Newspapers Association, made up of 180 news organizations, has granted the Mainichi its Grand Prix award on 21 occasions, making the Mainichi the most frequent winner of the prize since its inception in 1957.
On 15 January 2004, Mainichi Shimbun and MSN Japan announced they were to merge their websites. The partnership has been known as MSN-Mainichi Interactive, effective since 1 April 2004. On 18 September 2007, Mainichi announced the launch of their new website, mainichi.jp, which would include "heavy use of social bookmarking, RSS and blog parts" and would "pay attention to bloggers". The new website began operations on 1 October 2007, marking the end of MSN-Mainichi Interactive, being replaced by mainichi.jp. The English-language Mainichi Daily News also moved to the new website. MSN-Japan switched to Sankei Shimbun.