I would think this would be the other way around. First, the Japanese high command was not averse to continuing their war with America. In order to understand this, you have to know high factor national honor is to the Japanese and their Code of the Bushido. Even after the first atomic bomb was dropped, the military leaders still believed with the right combination of AA guns that such bombers and bombs could be hit while still in the sky. The Japanese even experimented with sound vibrations in which to knock down enemy craft! However, with the Russians, the Japanese were caught in a totally different situation. The Japanese knew that if they capitulated, the time would come where the Americans would eventually leave. If the Russians had occupied Japan, the Japanese knew that they might never leave. This largely mirrors real life as Russian and Japan are still disputing over some of the Northern Islands of Japan since the end of WWII.