Kyushu was the target of Operation Olympic, the first stage of the planned 1945 invasion of Japan.
Olympic was designed to seize the southern part of Kyushu, Japan’s southernmost main island. The invasion was tentatively scheduled for November 1, 1945, with Okinawa serving as a staging base for Allied forces and supplies.
The planned landings would have taken place at several locations, including Miyazaki, Ariake, and Kushikino. Captured airfields on Kyushu were intended to support the later phase of Operation Downfall, called Operation Coronet, which would have attacked the Kanto Plain near Tokyo on Honshu.
The invasion never happened because Japan surrendered in August and signed the formal instrument in September. Kyushu is sometimes confused with Honshu in this context: Honshu was the target of Coronet, while Kyushu was the target of Olympic. Together, Olympic and Coronet made up the larger Downfall plan.