No. Japan did surrender (after some negotiation and a relaxation of the "unconditional surrender" demand), so obviously it was part of their culture.

The generals were prepared to let the population burn, and calculated with the Americans having only one or two bomb cores left (there was one). What made them accept that the situation was hopeless was the Soviet declaration of war and invasion of Manchuria. Besides this leading to them losing the army on the mainland, they had hoped that USSR would be able to mediate on their behalf. With that hope gone, they had nothing to do but tell the Emperor to shut down the war.