Former English teacher morphs into star seller for Koolearn

How did a young English teacher become famous overnight and even drive up the shares of an education giant by as much as 700 percent in the stock market within a month?

My colleague Ma Si and I didn't know the answers until we interviewed Dong Yuhui, one of the most listened-to livestreamers in China these days.

When he first arrived wearing a black shirt, common sneakers and a calm face, nowhere could we recognize him as a big internet celebrity.