Which planned Allied invasion operation would have targeted Kyushu if Japan had not surrendered?

Operation Olympic was the planned Allied invasion of Kyushu if Japan had not surrendered.

Olympic was the first phase of Operation Downfall, the proposed invasion of the Japanese home islands. Allied planners scheduled it to begin on November 1, 1945, with landings on Kyushu, Japan’s southernmost main island.

The second phase, Operation Coronet, was planned for Honshu and was scheduled for March 1, 1946. Together, Olympic and Coronet would have formed a massive campaign against Japan, but neither operation took place because Japan accepted the Allied surrender terms in August 1945.

Operation Neptune is sometimes confused with Olympic because both were amphibious operations, but Neptune was the naval assault phase of the Normandy invasion in Europe. Operation Downfall was the overall Japan invasion plan, not the specific Kyushu operation.