The Mountain Village Operation Units were underground paramilitary units organized by the Japanese Communist Party (JCP) in the early 1950s for the purpose of carrying out Maoist-inspired guerrilla operations against the Japanese government and the Allied Occupation of Japan. The units were formed under the guidance of the Interim Central Directorate of the JCP, an informal group created by the party’s majority Shokanha faction, and sought to foment a nationwide communist revolution in emulating Mao Zedong's strategy of forming a base of operations in rural villages, but the operations achieved no successes and proved a disaster for the party's political prospects going forward.

The Red Purge was an anticommunist movement in occupied Japan from the late 1940s to the early 1950s. Carried out by the Japanese government and private corporations with the aid and encouragement of the Supreme Commander for the Allied Powers (SCAP), the Red Purge saw tens of thousands of alleged members, supporters, or sympathizers of left-wing groups, especially those said to be affiliated with the Japanese Communist Party, removed from their jobs in government, the private sector, universities, and schools. The Red Purge emerged from rising Cold War tensions and the Red Scare after World War II, and was a significant element within a broader "Reverse Course" in Occupation policies. The Red Purge reached a peak following the outbreak of the Korean War in 1950, began to ease after General Douglas MacArthur was replaced as commander of the Occupation by General Matthew Ridgway in 1951, and came to a final conclusion with the end of the Occupation in 1952.