I don't doubt for a moment these two soldiers are left over from WWII, but I seriously doubt these guys don't know Tokyo has not surrendered.
I wouldn't be to hasty in arriving at a conclusion. Many people my age can recall other such incidents many years after the war with Japan had ended. Of course the number of such incidents decreased almost exponentially with the years. The preceding such incident was deemed the last but as we see now, it wasn't the last. Let me just say I am not as skeptical as you.
actually there were a few who didnt believe it and continued to fight. in 1980 i think, the japanese sent a military rep there to tell them the war was over.