A couple of thoughts:

Yes, I’ve heard before, even from people living in Japan, that they are quite xenophobic.

Now, why is this not condemned from the west ? (I know Chinese people and they do remember WW2)

As everything several reasons:

Japan has a great propaganda machine to make their culture look cool AF: anime/manga, the mythology around temples, samurais, ninjas…

The good parts of their culture, specially in contrast to the west: the extreme politeness, how clean and organized they are, civility/safety, super good and maintained public services such transport…

The “pretend WW2 didn’t happen”. They were absolute monsters on WW2, way beyond the nazis, but the combination of doing a 180 towards the west and the atomic bombs made it so the west was comfortable with looking the other way while Japan conveniently forgets his war crimes (for anyone unaware search for Nanjing, be warned is a hard read, but is important not to forget)

The “pacifist xenophobia”. When you go to japan their way of practicing xenophobia is quite passive, like, let’s be clear, you are loud and disgusting for them, but they will never tell you that, and you are probably never going to be in danger. At least as a tourist this is 100% like this, they might even just feel introverted rather than xenophobic. From what I’ve heard from people living there, it gets more clear when you live, but didn’t get any “I’m in danger” feeling from them, so I guess that low key discrimination is like that.

Now, not saying any of that makes it good, but I can understand why there is a different level of pushback than to the USA for example, where if you are brown and meet an angry cop or redneck (or both), you might end up dead.

I know for the fucking internet there is no such thing as grey, is either black or white, but I think the world is more nuanced than that.

BTW, for their work culture alone I would never live there, and while I like an anime or two, I’m not an otaku by any means. I did enjoy my vacation on Japan several years ago, but not more than the one on China or other Asian countries.