 In 2003, U;Nee debuted as a dance-pop singer, with upbeat songs (although some of her songs were upbeat songs, she rapped in many of them), as heard in her very first single, "가" (Go).The song was well received by Korean media, and garnered her many fans.The track was then featured on her debut album, U;Nee Code, released on June 12, 2003.