> The one condition they had was that the emperor had to stay in place and should not be punished for the war. The US could have chosen to accept this condition and end the war, but didn't for a variety of reasons (none of them military).
They did end up doing so, but they insisted on unconditional surrender regardless. Even though they knew that they would end up meeting the singular Japanese condition.
The US occupation did leave the Emporer in place.