What was the codename for the planned second phase of the Allied invasion of Japan near Tokyo?

Operation Coronet was the planned second phase of the Allied invasion of Japan near Tokyo.

Coronet was intended to follow Operation Olympic, which would have captured southern Kyūshū. The target was the Kantō Plain on Honshū, the main Japanese island, with the objective of taking Tokyo and defeating Japan's remaining military resistance.

Planners tentatively scheduled the operation for spring 1946, after Olympic had created airfields and staging areas. The proposed force would have been extremely large, involving the U.S. First and Eighth Armies and additional Commonwealth formations. It was expected to exceed the scale of the Normandy landings if carried out.

Coronet is sometimes used incorrectly as a name for the whole planned invasion. The umbrella plan was Operation Downfall, while Olympic and Coronet were its two principal stages. Japan's surrender in August 1945 canceled both operations before either reached the battlefield.