Like many of her classmates, Xie Roumei, a 28-year-old accountant from China’s Fujian province, started using South Korean cosmetics in high school – a preference she carried into her twenties. Most of the eye make-up and beauty products she uses are still Korean, Xie said – a loyalty that has helped turn its cosmetics industry into a global powerhouse, with exports rivalling those of semiconductors and cars. Fuelled by the global appeal of K-pop, K-dramas and the “glass skin” ideal, the...