Kyushu was the target of Operation Olympic, the first stage of Operation Downfall. Allied planners intended to seize the southern part of Japan’s southernmost main island beginning on November 1, 1945.
The plan called for landings at several locations, including Miyazaki, Ariake, and Kushikino. Captured airfields and territory on Kyushu would have supported the later invasion of Honshu, known as Operation Coronet.
Okinawa, captured by Allied forces in June 1945, was intended to serve as a staging area for Olympic. The planned invasion was canceled when Japan accepted the Allied terms and formally surrendered before November arrived.
Kyushu is sometimes confused with Honshu because Tokyo is on Honshu and the second stage of Downfall was aimed at the Kanto Plain there. Kyushu was the first objective, not the final target of the overall invasion plan.