There are at least 50 of them, crowded into a low-ceilinged room with mirrors on three walls. It is hot, it is sweaty and it is 9.30 p.m. on a Wednesday night.
The group, who have been practicing the same move repeatedly for nearly two hours straight, are all students of Def Dance, an elite dancing and singing school in Seoul's upscale Gangnam neighborhood.
"I spend about three hours here every day after school," says Lee Jae-Gi, a skinny 16-year-old wearing a gray sweatshirt. I started taking classes when I was 11."
He studies K-pop, hip-hop and singing. "Practicing the same move over and over again can be tiring but I am progressing and that is all I care about," he adds.
The teenagers enrolled in Def Dance are all single-mindedly pursuing the same aim: to become a K-pop idol
. Becoming one of the chosen few guarantees fame, success and a bank balance that sets them up for life.
But the school, which charges $200 per month and has 1,400 students, some as young as eight, is only the first rung on the ladder to fame.