This is a German perspective : we don't feel accountable directly for what our vorfathers had done to harm other countries during WWII, because we are not the people doing the killing and looting. But we are ashamed for not acknowledging such crime. We didn't want to push our vorfathers too much because most of them also victims on some aspects, but in general we made a clear cut to them, to their faith and to their deeds.
This doesn't make Germany weak, but strong. I'm sure the Japanese society also deserves a bright future because none of you are those war murders. The global society will only be more and more on China and Koreas side on historical justice. A cut to the past is to earn a good future for Japan
MfG