Changsun

On August 12, 2021, he was introduced as the 33rd contestant of the survival show Wild Idol. During the show's finale, he was revealed to have ranked 1st overall, thus making him a member of TAN. They debuted with their first mini album Limited Edition '1TAN on March 10, 2022.

On September 25, 2023, Changsun announced through an handwritten letter posted on his Instagram that his contract with Choeun Entertainment had expired and decided to leave 24K. On June 29, 2024, Changsun announced on TAN's official fan cafe that the group had disbanded and he is stepping down as leader as he leaves the idol industry.