Chrystal Soo Jung, known professionally as Krystal Jung, was born on 24 October 1994 in San Francisco, California. She began her entertainment career as a trainee under SM Entertainment after being scouted during a family visit to South Korea, and debuted as the maknae and main vocalist of the girl group f(x) in September 2009 with the single "LA ChA Ta". Krystal Jung’s solo work included the Melody Project single "Melody" (2010) and the soundtrack contribution to My Girl (2014). She released the single "Solitary" on 27 November 2025. Throughout her tenure with f(x) she participated in collaborations such as "Spread Its Wings" with Luna and Amber for the drama God of Study and "Butterfly" with sister Jessica for To the Beautiful You. The group’s albums Pinocchio (2011), Pink Tape (2013), Red Light (2014), and 4 WALLS (2015) charted within the top ten of the Korean Gaon Albums Chart, while singles like "Chu~♡" and "I Love You, I Love You" reached the top twenty. Krystal Jung also appeared in television dramas including The Heirs (2013) and My Lovely Girl (2015), and served as a host on M‑Wave. Her career has been marked by consistent chart performance, multiple award nominations, and a sustained presence in both music and acting within the South Korean entertainment industry. "Solitary," her single released on November 27, 2025 entered Melon's Top 500 Melon domestic chart at rank 6 the next day.