Not OP, so I'm sorry if I misread the prompt, but here's what I think:
The Goldsteins are Jewish (at least, their last name is). There were Jews in Japan and China, (though I don't know about Korea) so the sisters could totally be Jewish and Asian-American, and that would be really cool! It would be cool because mainstream American movies don't get a lot of Asian-American main characters (or Jewish main characters). And representation matters (both to the people within and outside the group being represented).
Re: Racebending AU
The Goldsteins are Jewish (at least, their last name is). There were Jews in Japan and China, (though I don't know about Korea) so the sisters could totally be Jewish and Asian-American, and that would be really cool! It would be cool because mainstream American movies don't get a lot of Asian-American main characters (or Jewish main characters). And representation matters (both to the people within and outside the group being represented).