Shigeharu Matsumoto, an executive director and head of the editorial department at the Domei News Agency when it was disbanded Oct. 31, 1945, one month later began to issue a small evening newspaper called the Mimpo.

Domei had been Japan's governmentally sanctioned news agency in the 1930s and 1940s and came to function as an arm of the state during the war. It was disbanded under the Allied Occupation and its functions were divided between Kyodo News and Jiji Press.

In an editorial in the Mimpo's first issue, Matsumoto wrote: "One war has ended, but we are destined to wage another war. It is the war for the reconstruction of individuals and a democratic revolution."