In Operation Downfall, what was the codename for the planned invasion of Honshu near Tokyo?

Operation Coronet was the codename for the planned invasion of Honshu near Tokyo.

Coronet was the second phase of Operation Downfall, the proposed Allied invasion of Japan. It was planned for spring 1946 and would have targeted the Kanto Plain, the broad region surrounding Tokyo on Honshu, Japan’s largest island.

The proposed attack was to follow Operation Olympic, which would have captured southern Kyushu in November 1945. Allied planners intended to use airfields and bases secured during Olympic to support Coronet. The planned operation would have required an enormous force and was expected to be larger than the Normandy landings.

Japan surrendered before either invasion took place. Coronet is therefore a planned operation, not a campaign that occurred. It is also distinct from Operation Ketsugo, Japan’s defensive plan for resisting an Allied invasion of the home islands.