Seo Hye-jin is a beloved instructor at one of the city’s best hagwons, Korea’s after-school academies that extend test prep well into the night. She’s not only an academic star, but she’s ...

About 75% of all elementary through high school students in South Korea attend one or more of nation’s 80,000 hagwons. “ “So I had a similar question,” said Kim. “How does this work?