Kyushu was the target of Operation Olympic, the first phase of Operation Downfall.
Operation Olympic was scheduled to begin on November 1, 1945, and aimed to seize the southern third of Kyushu, Japan’s southernmost main island. The captured territory was intended to provide airfields and bases for the later invasion of Honshu, the largest Japanese island.
Okinawa, which Allied forces had captured earlier in 1945, was planned as a staging area for Olympic. Allied planners expected the Kyushu landings to require a very large naval and ground force, including fourteen U.S. divisions and additional units.
Kyushu is sometimes confused with Honshu because the second phase, Operation Coronet, was intended to strike the Kanto Plain near Tokyo on Honshu. Operation Olympic never took place: Japan’s surrender in August 1945 canceled the entire Downfall plan.