Several issues were banned by the Japanese police. We renamed it "Wen Zhi" and published it. With the support of Lu Xun and Guo Moruo, he successfully launched the left-wing cultural movement with other progressive literary publications and groups in Tokyo. During the same period, Ren also led the establishment of various social science groups to study Marxism and United the broad masses through these groups. "After the election of Japan's student unions, the leadership controlled by the Kuomintang for a long time was seized. "
Ren's activities have always been carried out under pseudonyms, but they are still listed by the Japanese authorities. It was not until the spring of 1937 that Ren Cai returned home safely under the cover of Ta Kung Pao reporter Yu Lichen.
After returning to China, he served as a teacher of Marxism-Leninism theory in Shanbei Public School and Kangda General School, and served as the head of political science and education department and the principal of army middle school in Kangda General School. During the War of Liberation, he served as the Minister of Propaganda Department of the Political Department of the Shanxi-Hebei-Shandong-Henan Military Region of the China People's Liberation Army and the Minister of Propaganda Department of the Political Department of the 18th Corps, and participated in the campaigns to clear Linfen, Jinzhong and Taiyuan on the Tongpu Line.
In the heavy work, Ren still participated in and supported the exploration, appraisal, arrangement and scriptwriting of Sichuan Opera with great enthusiasm. After retiring to the second line, he wrote an article for Sichuan Opera Art, wishing the adaptation and performance of The True Story of Ah Q a success. "The performance is faithful to Lu Xun's original work and innovative, which enriches Ah Q's character description and plays a connecting role in the development of the plot." In order to expand the influence of the play, Ren personally paid for provincial leaders and experts to watch it.