Oh Joon Seok is a South Korean singer, dancer and member of ATBO (에이티비오). He graduated from Gokjeong High School.
In early 2022, he participated in the survival show “The Origin – A, B, Or What?” under IST Entertainment (IST엔터테인먼트) and ended up 2nd place, qualifying to be a member of the show's project group.
He made his debut in July 2022 as ATBO's leader, main rapper and main dancer with their first mini-album, "The Beginning: 開花".
In September 2024, ATBO will join JUST B to form a special project group called THE CREW ONE (더크루원) to participate in the survival show "Road to Kingdom Season 2".