I'd be careful with claims on historical facts. Quite a few historians will tell you the "fact" that the Soviert declaration of war had a bigger impact than the devastation of Hiroshima and Nagasaki. I didn't matter for the Japanese if their cities were burnt down by one plane or 2000 since the US had any number at hand anyway.

The final vote in the High Council was 5 to 4 in favor of surrender. The tie-breaking vote was cast by the emperor.