In 1887, he established the Min'yūsha publishing company, which printed Japan's first general news magazine, the Kokumin no Tomo ("The People's Friend") from 1887 to 1898.

Sohō was initially a champion of liberal democracy and populism, as he felt that a free, open and democratic social and political order in emulation of the western nations in general, and the United States in particular would enable Japan to modernize and strengthen itself in the shortest possible time.

By the second half of the 1890s, he came to be regarded as a conservative champion of the Meiji oligarchy, and was a close confidant of Prime Ministers Yamagata Aritomo and Katsura Tarō.

While overseeing these publications as general editor, Sohō contributed some 350 articles, on diverse subjects ranging from international affairs, to history, biography and literature.

He also compiled Kinsei Nihon Kokumin shi (近世日本国民史 "A History of Early Modern Japanese People"), which was published in 100 volumes over a period from 1918 to 1952.