Which operation within Operation Downfall was planned to attack Japan’s Kantō Plain near Tokyo?

Operation Coronet was the planned second stage of Operation Downfall, targeting Japan’s Kantō Plain near Tokyo.

The operation was scheduled for spring 1946, after Operation Olympic had captured and developed positions in southern Kyushu. The Kantō Plain contains Tokyo and was considered the decisive objective because control of the region would place the Japanese political center and major population areas under Allied military pressure.

Coronet was never executed. Japan surrendered in August 1945, before Olympic’s proposed November landings and well before the planned spring 1946 assault. The cancellation avoided a campaign that Allied planners expected to be exceptionally difficult and costly.

Coronet is frequently confused with Operation Olympic, which targeted Kyushu. Both were components of Downfall, while Ketsugō was the Japanese defensive plan designed to oppose the expected invasion. The planned sequence—Olympic first, Coronet second—is the key distinction.