The estimation was over a million US soldiers and half a million British, along with a majority of the Japanese people and every prisoner of war in Japan.
Conquistadors were the Spanish soldiers that invaded and took lands from the Indians.
If you mean what happened to them at the end of WW2 then they were invaded by America (USA) and the USA dropped an atomic bomb on them as a symbol of strength to scare the Japanese and force them to surrender in which they succeeded. The US occupied Japan after dropping the atomic bomb, but it never invaded Japan. The reason for dropping the A-Bomb was to prevent the need to invade.
The "Conquistadores"
English and Spanish soldiers invaded and took lands from Indians.
Dunkirk. 338,000 Allied soldiers were rescued.
The Spanish invaded Latin America some of these conquers were Cortez, Pizzaro, etc.
great Britain have invaded south America for the first time
America invaded Normandy because we wanted to.
Xerxes
The Japanese never fully invaded America.
He had about 3000 soldiers and about 2000 Indian allies when he invaded Florida.
Xerxes