The influential student umbrella organisation Zengakuren (General Confederation of student self-governments) was established in 1948. It had numerous members and was initially close to the Communist Party.

From about 1957, however, it began developing far-left, anti-Stalinist positions that were independent of the Communist Party and the Socialist Party. This representative of the New Left played an important role in the student riots in 1960 and in the protest movement from 1968 and 1969. During this period of radicalisation, Zengakuren split into various competing factions.