Kum Jun Hyeon

On December 29, 2022, Junhyeon was introduced as a contestant on Boys Planet, which began airing on February 2, 2023. He ranked 14th place overall in the finale episode, thus being unable to debut with ZEROBASEONE. On April 26, 2023, Redstart ENM announced that he, along with fellow Boys Planet contestants and labelmates Kim Min Seoung, Hong Keon Hee, and Choi Woo Jin, would be holding their first fanmeeting titled REDSTART BOYS 1st Fanmeeting "This Time is Our Turn" in Korea and Japan as TIOT.

On January 4, 2024, it was announced that the he would release the digital single "WWW" on January 9. TIOT debuted on April 22 with the mini album Kick-Start.