I'm a mix raced Malaysian (my mom's ethnicities is bidayuh and my dad, his dad is Iban and his mom Chinese) and while the issue of racism are of course from the different races (the Malays, Chinese, Indians and the indigenous like the Ibans and Bidayuh), each races has their own sub ethnicities and they are also racist towards each other. Maybe not as overtly nowadays as it's used to but you can still hear it from the boomers. Like the Chinese, there's the Hokkien, Cantonese, Hakka, Teochew, Hainan, Foochow and Kwongsai. There are other sub ethnic groups form by Chinese migrants that has assimilated with the locals like the Baba-Nyonya, the Sino and the Peranakans. Too other races, they're all Chinese but growing up in the early 2000s as a kid, you can see Hokkien and the Hakka's distaste for each other. They don't even speak the same dialect. The Hokkien and the Hakka's distaste for the Foochow.

Same goes for the Japanese. People think it's one big race. What people think of a typical Japanese is actually the Yamato and sometimes the Aynu. Then there's the Ryukyuans and Bonin islanders. The latter two have been looked down upon a lot and have been the victim of institutional racism on many occasions.