The end of WW2 was a complex political issue, and the atomic bombs were not the 'press here, end war' that most of us believe.

The Japanese we're holding out hope (stupidly) that the Soviet Union would negotiate a conditional surrender with the united States as the end of the imperial system was unacceptable to them. The US had floated that if there was an unconditional surrender, that the imperial system would stay intact, but wanted it to seem like a US condition, not a Japanese one, because that would be a conditional surrender.

The Soviets always intended to invade, but were held by a nonaggression pact they made with the Japanese. The US pressured the Soviets very hard to violate this and invade Manchuria.

There was literally a Japanese war cabinet convened already when news of Nagasaki reached them. We have actual primary source for their reactions. They did not care.

Only once the second bomb dropped and Manchuria was invaded did some of the cabinet manage to convince the emporer to intervene which was extremely rare.