WW2 denialism is apparently very common in Japan. Not only their history books deny any Japanese atrocities but I suppose they deny that their friends did anything either.
Controversy over history textbook content is a recurring theme in postwar Japan. There are some really despicable characters in the government, the education bureaucracy, academia, and (ultra-)nationalist circles continuing to push this. That being said, they do not get a free pass here. Plenty of academics, teachers, and citizens have protested the playing down of wartime atrocities and their position gets plenty of attention. In addition, textbooks which do give attention to the "dark" side of Japanese history are readily available as are similar supplementary materials.
You might find http://spice.stanford.edu/docs/134 interesting.
As for the idea that "
they deny that their friends did anything either", some may, but not many.
On a side note, years ago I came upon a little store in Shibuya (Tokyo) that sold Nazi memorabilia. You could buy a genuine SS cap for an astronomical sum, or a fake for considerably less (but still a lot). I suspect that there is a strange fascination with all things Nazi in many countries. Like I said, though, this was an obscure store and hardly reflects general Japanese attitudes toward Nazism.
Also years ago, when my parents came to visit me, we took a taxi in Kyoto, and after I got to talking to the driver, he thanked my dad profusely for his participation in the occupation. "Makete hontou ni yokatta." He was very thankful that Japan had lost the war. I suspect that many (most?) share this sentiment.