 In 1922, as younger converts to Bolshevism were becoming impatient, Yamakawa along with Sakai and Arahata agreed to found an illegal Communist Party.Yamakawa wrote the essay "A change of course for the proletarian movement" in August 1922, which was in fact a manifesto for the new Communist Party.In it, he criticized the anarchist faction which had been dominant within the socialist and labour movement in Japan for being idle dreamers who failed to obtain anything concrete that actually benefited the working class.