Marco

In high school, Marco had auditioned to become a comedian for KBS during their open auditions but had failed. On August 16, 2017, Marco debuted as a member of HBY with their single album "Make It Ride" In late 2017, he participated in the KBS survival show The Unit. On February 10, 2018, the final episode was aired where Marco was announced in fifth place and thus making him a member of Unit B, the then unnamed project group.

He then made his debut as a member of UNB on April 7, 2018 with their first mini album Boyhood. Unfortunately, UNB disbanded on January 27, 2019 following the conclusion of their final Japanese concert. Sometime in March 2020, HBY unfortunately disbanded after announcing it on their Daum Cafe.