What was the planned second stage of Operation Downfall called?

The planned second stage of Operation Downfall was called Operation Coronet.

Coronet was designed as the follow-up to Operation Olympic, the proposed invasion of southern Kyushu. It would have attacked the Kantō Plain near Tokyo on Honshu, Japan’s largest main island, after Allied forces had established positions farther south.

The tentative target date was March 1, 1946. Coronet was expected to be larger than Olympic because it would have involved a major drive toward Tokyo and the deployment of numerous Allied divisions. Planning included American armies and a proposed Commonwealth contribution.

Coronet was never executed. Japan surrendered in August 1945 after the atomic bombings of Hiroshima and Nagasaki, the Soviet declaration of war, and the invasion of Japanese-held Manchuria. Operation Pastel was a related deception plan, while Operation Majestic was a later name associated with Olympic after its original code name was compromised.