I totally get it!!! I'm a Chinese person who's spent a lot of time in western queer/trans spaces as well, and I completely did not understand the overwhelming whiteness in all of those, until I slowly realized nobody wanted to talk to me. Just by existing I sort of rocked the boat in those spaces, since with me around they couldn't make crass or insensitive jokes about Asians anymore, despite the fact they shouldn't be doing so to begin with. It was so bizarre, I agree.
The thing with Japanese media in particular -- a lot of it is 'palpable' to a white audience in the way that Chinese and Korean media isn't. It's sort of easy to cling to if you're white because fundamentally Japanese values and imperialism are very similar to the west. At the same time, a lot of white people don't like to acknowledge the humanity of Japanese people, like you've said, so it turns into something that's nearly wholly fetishistic and orientalist. I still think about the white trans woman I met at a party once who called herself by a Japanese name.
As with south east asia, there's a complete non-acknowledgement of that region by the west due to their lack of 'oriental value' beyond maybe food. I remember at school people didn't know where Indonesia was, despite how big it was across the map. Since I have family in Singapore and the surrounding countries, it only made it even more crazy as I realized growing up that nobody outside of south east asia likes to talk about it. And those that do? Well... it's sometimes hard to discern intentions. For example, there's a Japanese singer that bases off a lot of her songs with words from south east asian languages, and despite the obvious marketing tactic of catering to south east asia doing this, she gets away with it due to those within south east asia happy there's people interested in our culture. It's a greater problem of racism and imperial powers against those that have been robbed. One of my friends worded it quite well: you're either the colonized or the colonizer.
Thank you so much for reading and commenting! I'm very happy to see another south east asian around :) I'll check out your work some time as well!