I was aware that Japan tends to do this and there wasn't as much of it as I expected, but it's still there in the movie.
It's like having a movie about a Confederate soldier suffering after the South lost the Civil War, which doesn't mention slavery or black people at all. You can say that your movie is about one of the soldiers who didn't keep any slaves himself and was just suffering because of the actions of people he had nothing to do with. In a way this could be true.
If you were to make this movie, it would still be raked over the coals, because slavery is such an important aspect of the Civil War that if you just leave it out, you're presenting a very skewed perspective, regardless of whether the individual soldier kept any slaves. World War II was an aggressive war which in the Pacific was started by the Japanese, and they did a lot of bad things quite aside from just invading. The movie pretends that the war was "the Japanese suffered", but not "the Japanese caused suffering".