Park Gun Wook

On August 10, 2021, Park Gun Wook was introduced as the 16th contestant of the survival show Wild Idol. Unfortunately, he was eliminated in the final episode, thus making him unable to become a member of TAN. On December 29, 2022, he was introduced as a contestant of Mnet's survival show Boys Planet, representing Jellyfish Entertainment.

During the show's finale, he was revealed to have ranked 5th overall, thus making him a member of ZEROBASEONE. The group debuted on July 10, 2023 with the mini album Youth in the Shade. On February 9, 2026, WAKEONE announced that Gun Wook and fellow ZEROBASEONE member Seok Matthew have signed exclusive contracts with the agency, fully transferring from their previous agencies.