The sinosphere has been very influential. So no doubt there would be Chinese diaspora in neighboring countries.I feel like the author doesn't know geography. This chapter made multiple references to China, but the past chapters clearly pointed at Thailand instead.
When she escaped the island in chapter 39, she landed in Thailand.
When she left for Japan in chapter 51, she departed from Thailand. She travelled through Laos, possibly Vietnam, and finally reached Japan via China. But she clearly met her master in Thailand and broke those pots in Thailand, not China.