Attended Doshisha University in Kyoto.
After attending Doshisha University in Kyoto for a time, he withdrew in 1897 and went to Tokyo. In 1900 he was accused of lese-majesto because of a magazine published by himself and a friend and was sentenced to three years in prison. In 1906 he participated in the formation of the Japan Socialist Party. He also acted as editor and writer for the daily newspaper Heimin Shimbun. In 1908 he was among those sent to prison for displaying anarchist slogans at a gathering in Kanda in Tokyo.
In 1916 he joined the Baibunsha, an advertising and publishing company founded by Sakai Toshihiko and, along with Sakai and Takabatake Motoyuki, edited a magazine called Shinshakai. He soon distinguished himself as a leading writer on Marxist theory. In 1922, at the time of the founding of the Japan Communist Party, he published articles in the magazine Zen'ei in which he called upon socialism in Japan to become a truly popular-based and law-abiding proletariat party. In 1928, he severed his connections with the Communist Party.
From around this time, he became active as a spokesman for a group known as the Ronoha, or Labor Farmer Faction. In 1937 he was among the left-wing leaders arrested in connection with the antifascist movement known as the jimrnin sensen. After the war, when the Communist leader Nosaka Sanzo returned to Japan in 1946, he attempted to start a new movement called the minshu jimrnin sensen, but met with no success. From 1951 on, he was active as a leading theorist of the left-wing faction of the Socialist Party.
His wife, Yamakawa Kikue, (1890- ) was a leader in the socialistwomen’s movement and the first head of the Women and Minors Bureau of the Ministry of Labor.