Which operation was the planned Allied invasion of Honshu’s Kanto Plain near Tokyo?

Operation Coronet was the planned Allied invasion of Honshu’s Kanto Plain near Tokyo.

Coronet was the second phase of Operation Downfall, the proposed Allied invasion of Japan. It was planned to follow Operation Olympic, which would first have seized southern Kyushu and provided bases for further operations. Coronet was tentatively scheduled for March 1, 1946.

The Kanto Plain was chosen because it included Tokyo and offered a broad area for a major landing and advance. The operation was expected to be larger than Olympic, with American forces landing near Sagami Bay and the Boso Peninsula before driving toward the capital.

Japan’s surrender made Coronet unnecessary. The operation’s name is often confused with Downfall, but the terms describe different levels of planning: Downfall was the complete invasion plan, while Coronet was the planned Honshu phase. Olympic was the earlier Kyushu phase.