Woo Sung-hyun, better known as Kevin Woo, is a South Korean-American singer-songwriter. He was born on November 25, 1991, in Danville, California, to a South Korean family. He began his musical career after being discovered by XING Entertainment at the age of 15, moving to South Korea to pursue training. Kevin Woo debuted as part of the boy group XING in 2006, releasing three singles before leaving the group in 2008. In August of that year, he became a member of the group U-KISS. U-KISS released several albums and singles, gaining popularity both domestically and internationally. During this time, Kevin Woo also began exploring a career in TV hosting and acting. In 2013, he joined U-KISS' first sub-unit, uBEAT, which released the EP I Should Have Treated You Better in 2013. He continued to appear in various dramas and musicals, including Summer Snow in 2013. In 2017, Kevin Woo left U-KISS to embark on a solo career, debuting with the single "Ride Along" in 2018. This led to the release of his first EP Treasure (2018), featuring the single "Freedom." In 2021, he released his first English-language single, "Got It," co-produced by Shintaro Yasuda. He made his Broadway debut in the K-pop-inspired musical KPOP in 2022.