Yu Seul Ki is known to be a backup dancer of Red Velvet, and she's been receiving praises for her pretty looks and dancing abilities from K-pop supporters since then. She has stable Instagram followers where most of them were K-pop fans and being a stunner, people think she can actually debut as a K-pop idol if she ever feels like changing her career. 4. Jeong Seonmin (Photo : Pinterest) When Somi released her debut track, "Birthday" in 2019, her backup dancer indeed stole the attention of fans with her stage presence. After appearing on music shows, she became a hot topic on Korean online communities due to her K-pop idol-like visual.