Hmm, I think every country commits crimes during war, it's a natural part of war itself which is a violent and inhumane activity. It's sad that to take down aggressors like the Nazis and Imperial Japan, you of course have to turn to war yourself, and every man has a point where war can turn him into a violent animal. US soldiers did all kinds of disgusting things when they took Japan, particularly rape.
But genocide is another level, and much of what imperial Japan did was as bad, or even WORSE than the Nazis. Imperial Japan was as racist, as violent, and as hideous as Nazi Germany. That's just a sad fact that I think Japan itself couldn't face. It couldn't deal with the idea that they were pretty much Nazis themselves. The Nazis were more systematic about it, but the Japan were...omg...so unBELIEVABLY brutal. Really. How can you look past that. The Imperial Japan war crime record is VAST. Perhaps we don't even know all the truly vile things they did.
And when I'm in this society in this day and age I appreciate all the people around me for being individuals, and I don't begrudge anyone if they either don't know or don't care to make a judgement about that time. I can separate history from where I am now and who I am with. I don't think it has anything to do with Japanese people, but a complex and very confusing relationship between the various bodies of power, and the mixed messages of religion and history. But if you are in an environment where you can talk openly about it (and of course, at an enkai is the worst idea ever), how can you fully equate what Japan did with the USA.
Though still, in reflection dropping the bomb was kind of...hmmm..fuzzy to me...I mean...it ended the war...but you don't kill civilians!! So, damn. I can't make a call on that one. It seems kind of sick to attack the most innocent to end the war, or to justify stopping more violence later that can hardly be quantified. That judgement call is FAR above my pay grade, thank goodness.
Just cos Japanese troops were massacring innocent people, how could you possibly think that means you should hurt THEIR civilians. Leave civilians of any race or creed ALONE!!!
Stuff is too complicated.

I also hope nobody is offended by what I said. I'm stating basic truths...and some of these truths are the ones people don't want to see because it's too hard. But any sane person can totally separate all that from modern day Japan, which is an entirely different beast...with ups and downs, but not like Imperial Japan! It's so different!