Kyushu was the main target of planned Operation Olympic.
Operation Olympic was the first phase of Operation Downfall, the proposed Allied invasion of Japan. It was scheduled to begin in November 1945 and aimed to seize the southern third of Kyushu, Japan’s southernmost main island. Allied planners intended to use captured airfields there to support the later invasion of the Kanto Plain near Tokyo.
The island’s location made it strategically important. Kyushu was closer to Allied bases and offered sites from which aircraft could support later operations against Honshu. Okinawa, captured by the Allies in June 1945, was planned as a major staging area.
Operation Olympic never took place because Japan accepted the Allied surrender terms in August 1945. The planned second phase, Operation Coronet, would have targeted the Kanto Plain. Olympic should therefore not be confused with Coronet: Olympic concerned Kyushu, while Coronet concerned the Tokyo region on Honshu.