On May 20, 2021, he was revealed as a contestant for SBS's audition show LOUD. Unfortunately, he was eliminated in the fifth round, which was the episode aired on August 14.
2022: BRANDNEWZ and YOUNITE
On January 7, 2022, Kyungmun was introduced as a member of the male trainee group BRANDNEWZ through a cover of Audrey Nuna's "Damn Right".
On February 18, he was announced as a member of the upcoming group YOUNITE. They debuted on April 20, 2022 with the EP, Youni-Birth.
On April 24, 2022, it was announced on the fancafe that Kyungmun had felt pain on his right elbow during the group's performance on Inkigayo. After he went to a medical facility, it was said that he will be wearing a partial arm cast and will continue to participate in the group's activities unless anything changes.