Answer:
I don't know what you mean about Japan refusing to surrender but maybe this could be helpful. don't copy word for word. I have two answers for u. hope I helped.
1. After the Hiroshima attack, a faction of Japan's supreme war council favored acceptance of the Potsdam Declaration, but the majority resisted unconditional surrender. On August 8, Japan's desperate situation took another turn for the worse when the USSR declared war against Japan.
2. Washington has believed ever since that the atomic bomb decisively forced Japan's surrender. ... With defeat imminent, Japan's leaders feared that without the imperial house, the state and their own power would be devalued and diminished in the eyes of the people, and that the state would ultimately disintegrate.