What was the planned second phase of Operation Downfall, targeting the Kanto Plain near Tokyo?

Operation Coronet was the planned second phase of Operation Downfall, targeting the Kanto Plain near Tokyo.

Coronet was intended to follow Operation Olympic, the planned invasion of southern Kyushu. Allied planners expected Olympic to provide airfields and positions that could support the much larger assault on Honshu, Japan’s largest island. Coronet was scheduled for spring 1946.

The Kanto Plain included Tokyo and surrounding areas, making it a strategically decisive target. Capturing the region would have placed the Allied forces near Japan’s political and industrial center. The plan reflected the expectation that Japan might continue fighting even after losing its overseas empire.

Coronet was never launched. Japan announced its acceptance of the Allied surrender terms in August 1945, before the planned invasion dates. The names are easy to mix up: Downfall was the overall invasion plan, Olympic was the Kyushu phase, and Coronet was the Tokyo-area phase.