Kim Hyo Jin, known simply as Hyojin, is a South Korean singer, dancer and member of ONF (온앤오프; short for ON N' OFF). He graduated from Jangchung High School and was enrolled in the Musical Studies program at the International University of the Arts but dropped out. He later earned a bachelor's degree in Japanese from Hanyang Cyber University. Before debuting, he was a trainee for 5 years and was introduced as part of WM Boys with their first appearance as B1A4's backup dancers at the 2016 Dream Concert in Seoul. He was featured as a dancer in the Korean version of the web drama "Loss:Time:Life" and gave a performance at IDOLCON just a few months before debuting. He made his official debut in August 2017 as the group's ON Team leader and main vocalist with their 1st EP, "ON/OFF". Weeks later, he entered the survival competition "MIXNINE" and finished in 2nd place, however, the companies could never reach an agreement and the project group that was planned after the show never got to debut. In 2018, the group signed a contract with Victor Entertainment (ビクターエンタテインメント) and made their Japanese debut and held a concert in Tokyo. In 2020, all the members entered MNet's "Road to Kingdom" and finished in 2nd place, and he had his acting debut with a role in the web drama "Can I Step In?". In 2021, all members (except U) decided to enlist for their mandatory military service around the same time, so he enlisted on December 28 and was discharged on June 27, 2023. Earlier in 2023, his agency, WM Entertainment (WM엔터테인먼트), released his solo debut, "Love Things", which was recorded before enlisting in the military. The group is now active again.