What was the Allied plan for a full-scale invasion of Japan if it had not surrendered in 1945?

Operation Downfall was the Allied plan for a full-scale invasion of Japan if Japan had not surrendered in 1945. The plan was never carried out because Japan accepted the Allied terms in August.

Downfall had two major stages. Operation Olympic was planned as the invasion of southern Kyushu, while Operation Coronet was intended to follow with an assault on the Tokyo Plain on Honshu. Olympic was scheduled for November 1945, and Coronet for March 1946.

The invasion planners expected fierce resistance from Japanese military forces and civilians. The atomic bombings, the Soviet declaration of war, and internal Japanese political decisions changed the situation before Downfall began. Because Olympic and Coronet were components of Downfall, they are sometimes incorrectly offered as the name of the entire invasion plan.