Kammala jumla mai zuwa: Operation Downfall shine shirin da Allied ya gabatar don mamaye tsibirin tsibirin Japan a kusa da ƙarshen yakin duniya na biyu. An soke aikin da aka tsara lokacin da Japan ta mika wuya bayan bama-baman nukiliya na Hiroshima da Nagasaki, da sanarwar yakin Soviet da kuma
mamayewar Manchuria. Wannan aikin yana da sassa biyu: Operation Olympic da Operation Coronet. An saita don farawa a watan Nuwamba na 1945, Operation Olympic an yi niyyar kama kudancin kashi uku na kudancin tsibirin Japan, Kyūshū, tare da tsibirin Okinawa da aka kama kwanan nan da za a yi amfani da shi a matsayin yanki. A farkon 1946 zai zo Operation Coronet, shirin mamayewa na Kantō Plain, kusa da Tokyo, a babban tsibirin Japan na Honshu. Gidajen jirgin sama a Kyūshū da aka kama a cikin Operation Olympic zai ba da damar tallafawa iska ta ƙasa don Operation Coronet. Idan Fall ya faru, zai kasance mafi girman aikin amphibious a tarihi.