My first hand accounts mostly come from my Father. He was a young Marine Corp officer on Okinawa during World War II. What a sad and terrifying time. He was stationed next to an air base on Okinawa and was issued a gas mask after the bombing of Hiroshima in preparation for the retalitory strikes they expected.
After Japan surrendered, there was a sudden shift in roles as the soldiers packed up and prepared to return the the USA. At one point, with little to do, he was offered a ride on a plane that was heading over to the mainland of Japan for some reason. He got to see Hiroshima and Tokyo, spending some time on the ground and interacting with a few Japanese citizens there. My father passed away a couple of years ago and I wish that my brother and I could have recorded his accounts of some of these things.