Actually many Japanese ladies have brown skin as well, as I am in Indonesia see many of them despite the white skin one is more on majority.
I think Chinese has more fetish on white thing, I mean they have ton of brown skin people in Southern China but their recent movie and singers are dominated by white skin one from North.
In the past, Hongkong movie shows many brown skin Chinese ladies as movie star
If you look on the new version of the same movie, it is dominated by white skin players. Same thing with other serials.