Mizuguchi Yuto, known professionally as U, is a Japanese singer, dancer and member of ONF (short for ON N' OFF). Before debuting, he was a trainee at JYP Entertainment for 1 year and, after switching companies, he was introduced as part of WM Boys with their first appearance as B1A4's backup dancers at the 2016 Dream Concert in Seoul. He gave a performance, alongside his groupmates, at IDOLCON just a few months before debuting. He made his official debut in 2017 as member of sub-unit OFF and main dancer, lead rapper, sub-vocalist and current maknae of the group with their 1st EP "ON/OFF". Weeks later, he entered the survival competition "MIXNINE" and finished in 23rd place. In 2018, the group signed a contract with Victor Entertainment 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 for him due to his Japanese citizenship) decided to enlist for his mandatory military service around the same time. The following year, he entered "Be Mbitious” in order to be selected as part of Rain's crew that was going to compete in "Street Man Fighter", but he was eliminated in the preliminary auditions. With all the other members now back from their military service, the group is now active again and has already held a fan meeting and participated in the RBW 2023 Summer Festival "Over the Rainbow".

(Source: Korean = Namu Wiki || Translation = MyDramaList) Edit Biography