What were the two planned operations that made up the Allied invasion plan called Operation Downfall?

Operation Downfall consisted of Operation Olympic and Operation Coronet.

Olympic was planned as the first stage, targeting southern Kyūshū in November 1945. Its purpose was to seize territory and airfields that could support the larger follow-up operation. Coronet was planned for spring 1946 and would attack the Kantō Plain near Tokyo on Honshu.

The invasion plan was canceled after Japan surrendered. Downfall therefore never became an actual campaign, although extensive Allied preparations had been made and Japanese forces had organized defenses against a possible invasion.

The plan is often confused with Operation Overlord, the Allied invasion of Normandy in 1944. Downfall would have been an invasion of Japan’s home islands, while Overlord was the operation that opened the major Western Allied front in Europe.