Kyushu was the target of Operation Olympic, the first phase of the planned Allied invasion of Japan. The operation focused on capturing the southern third of Japan’s southernmost main island in November 1945.
Allied planners wanted Kyushu airfields to support the later Operation Coronet. Coronet was intended to attack the Kanto Plain on Honshu, the island containing Tokyo. Together, Olympic and Coronet formed Operation Downfall, the proposed invasion of Japan’s home islands.
Kyushu was selected because its southern areas offered potential landing beaches and because airbases there could support operations against the rest of Japan. Japanese leaders anticipated the broad plan and organized Operation Ketsugo to defend the home islands.
Kyushu is sometimes confused with Honshu because both were central to the proposed invasion. Honshu was the target of Coronet, not Olympic. The surrender in August 1945 canceled the planned landings before either operation began.