@TjapDjemboet
1. unless, over 90% all fiction has japan made is sexual & slavery theme?
Do you understand the difference between fantasy and reality? In the first place, Japan did away with slavery much earlier than their European counterparts, in the 15th century. There has not been any system of slavery since then. The reason for the slavery theme in their isekai stories, are for two reasons, one being that they believe it was normal for there to be slavery in that kind of setting, and two, because they already did away with slavery way earlier than Europeans, they wanted to show their higher moral ground.
2. no sincerely apologies for victim country nor compensation like german did to jews from goverment?
Where did you hear this from? Communist China and racists, right? You didn't know that they regularly give development grants and financial aid to Southeast Asian countries since the 80s? As for apologies, who told you they never apologized? There has been numerous apologies made by Japan, the only difference was, whether their apologies were accepted or not. China refused to accept their apologies, with the first famous refusal being by Mao himself, who said Japan needn't apologize, because if Japan didn't attack China, Communists wouldn't have gotten China. Don't believe me? Research yourself, don't listen to gossips.
3. if so as a child you dont have obligation to apologize/give compensation for victim and not to do same sin?
The Japanese are already beating themselves and their children over what has happened. Do you expect every generation to bow their heads and beg for apology from every country in every generation? The Japanese already pledged not to do the same sin since they lost the war. It wasn't America that told them to disarm, America wanted Imperial Japan to continue. It was the Japanese themselves who disarmed and became a pacifist country post-war because they were afraid that if they took up arms again, they would repeat history. This fear is unfounded, but this fear has been deeply rooted in Japanese society that the idea of war terrorizes them a lot.
You say a child has an obligation to apologize, compensate for the victim? Okay, let's imagine your father was a rapist. You apologize and compensate the victim. With me so far? Now, you tell your child to also apologize and compensate your father's victim. And you also tell your grandchilden to apologize and compensate for your father's victim. Is that acceptable to you? Is that fair to you? That's what you're trying to say when you ask today's Japanese people to apologize for what happened in WW2.