Yoo Yong-ha is a South Korean singer, dancer, former member of 1THE9 and current member of WEi. He graduated from Jeonnam Technical Science High School. He appeared in the singing survival show "UNDER19" and by finishing in 6th place, he was able to join the project group. He made his debut in April 2019 as 1THE9's leader, lead rapper and vocalist with their first mini-album, "XIX". They were supposed to be active for around one year, so in August 2020, PocketDol Studio announced their disbandment. He returned to his agency, OUI Entertainment, and re-debuted in October 2020 as WEi's lead rapper and sub-vocalist with their first EP, "Identity: First Sight". They have enjoyed some popularity, especially in Japan.