Krystal debuted with f(x) in 2009. f(x) is a South Korean girl group formed by SM Entertainment. The group originally consisted of five members: Victoria, Amber, Luna, Sulli, and Krystal. f(x) debuted on September 5, 2009, with the digital single "La Cha Ta".
The Ultimate Krystal Jung Quiz: Prove You're a True Fan