What was the planned Allied invasion of Honshu near Tokyo called in 1945?

The planned Allied invasion of Honshu near Tokyo was called Operation Coronet.

Coronet was the second stage of Operation Downfall, the proposed Allied invasion of Japan. It was planned for spring 1946 and would have targeted the Kanto Plain on Honshu, the main Japanese island and location of Tokyo.

The operation was designed to follow Operation Olympic, the planned landing in southern Kyushu in November 1945. Bases captured during Olympic would have supported the air and naval forces needed for Coronet. The proposed assault would have been larger than Olympic because it aimed at the heavily populated region surrounding Japan’s capital.

Japan’s surrender in August 1945 canceled Coronet before any landings occurred. It is therefore important not to confuse the codename with Downfall: Downfall referred to the overall invasion plan, while Coronet referred specifically to the Honshu phase.