This may not be as useful, but:
I actually discussed this topic with my host family, and they were, from what I understand, quite aware that a lot of horrible things occurred during the war. The government wasn't exactly being honest about telling its people about its intentions or its success rate; even as bombs rained upon the Home Islands, news reports were still proclaiming imminent victory. It was only later, when the soldiers came home, that the truth began to come out, but by that point, Japan had to rebuild, and so they needed to focus on that rather than coming to terms with the war itself.
That is, at least, what I could tell. Keep in mind that I stayed in Hiroshima -- the city which issues protests every time a nation tests a nuclear weapon, regardless of what nation it is.