What was the codename for the planned first stage of the Allied invasion of Japan, targeting Kyūshū?

Operation Olympic was the planned first stage of the Allied invasion of Japan, targeting Kyūshū.

Olympic was designed to capture the southern third of Kyūshū, Japan's southernmost main island. The landings were scheduled for November 1945, several months after the Japanese surrender eventually made them unnecessary.

The second stage, Operation Coronet, was intended to invade the Kantō Plain near Tokyo on Honshū in early 1946. Together, Olympic and Coronet formed Operation Downfall, the overall invasion plan.

The operation was canceled after Japan accepted the Potsdam Declaration. The atomic bombings, the Soviet entry into the war against Japan, and the rapid collapse of Japan's strategic position all contributed to the surrender before Olympic could begin.