Jia

On July 7, 2021, she was confirmed as a contestant on Mnet's newest reality show Girls Planet 999, along with the other participating trainees, through the prologue trailer. Her official profile was released on July 17. In the eighth episode, which was aired on September 24, it was revealed that Jia was unfortunately eliminated and had ranked K11.

On July 10, 2022, Yoon Jia announced through her personal Instagram that she would make her debut as a member of YES IM's upcoming girl group mimiirose. They debuted on September 16 with the single album "Awesome". On November 21, 2023, it was revealed that mimiirose had parted ways with YES IM Entertainment through a mutual decision.