Kyushu was the target of planned Operation Olympic in the 1945 invasion of Japan.
Operation Olympic was the first stage of Operation Downfall, the proposed Allied invasion of the Japanese home islands. Allied planners intended to land on southern Kyushu in November 1945 and establish bases for the later Operation Coronet, which would have targeted the Kanto Plain on Honshu near Tokyo.
The planned assault reflected the geography of Japan's main islands and the need to secure airfields and ports before any larger campaign. U.S. military planners expected extremely difficult fighting because Japanese forces were preparing extensive defenses and mobilizing civilians.
Japan surrendered before Olympic began. The decision to accept the Allied terms in August 1945 meant that the projected invasion, its troop movements, and its planned naval support were canceled. Kyushu therefore remained a planned objective rather than an invaded battlefield.