My guess, and it’s just a guess, is that the leaders are banking on the harvest in Manchukuo getting through the blockade, and then creating such a bloodbath during the invasion that the surrender will not be unconditional. Two things that they are not banking on are the atomic bombs and the Soviets, who are technically neutral, invading Manchuria.
If the leadership thinks anything is getting through the blockade at this point, they are delusional. Not only that, but even if any stocks of food had been delivered from Manchukuo, there was no way to distribute it to the people. So much of the Japanese strategy was based on wishful thinking. Or maybe the leadership was so out of touch with the situation they didn’t know just how badly the daily economic fabric of Japanese society had been shredded.
The point is that dropping the bombs was made inevitable and unavoidable buy such pig-headedness. Even