Which operation was the planned 1946 Allied assault on Japan's Kanto Plain near Tokyo?

Operation Coronet was the planned 1946 Allied assault on Japan's Kanto Plain near Tokyo.

Coronet was the second phase of Operation Downfall, following Operation Olympic's proposed invasion of southern Kyushu. Its tentative start date was March 1, 1946, and the objective was to land on the Kanto Plain, drive inland, and capture Tokyo. The planned assault would have used beaches near Kujukuri on the Boso Peninsula and Hiratsuka on Sagami Bay.

The projected force was even larger than Olympic's. Up to 45 U.S. divisions were assigned for the initial landing and follow-up operations, compared with 12 divisions in the initial Normandy landings. The plan included the U.S. First Army and Eighth Army, with additional forces expected to arrive later.

Coronet never occurred because Japan surrendered in August 1945. The operation's name is often mixed up with Olympic, the Kyushu phase, or Downfall, the overall invasion plan. A temporary alternative name, Operation Majestic, was adopted after the name Olympic was compromised in insecure communications.