Onesun (원썬), born Kim Seon-il (김선일) on November 17, 1978, is a South Korean rapper known for his contribution to the underground hip-hop scene. He debuted in 2001 under Masterplan, a label recognized for fostering Korea’s early hip-hop talents. Over the years, he has remained an influential figure in the industry, blending old-school and socially conscious rap elements into his music. Onesun released his first studio album, One, in 2006, followed by New Old School in 2010. His early EP, For Whom (2003), helped establish his presence in the scene. Throughout his career, he has dropped numerous singles, including "Fisherman’s Song" (2001), "(Re)Define" (2009), and "Shinin’ Ground" (2021). His music often reflects his experiences, lyrical storytelling, and a deep-rooted appreciation for classic hip-hop. Beyond music, Onesun has been active in South Korea's hip-hop community, collaborating with various artists and engaging in cultural movements. His 2018 single "March for the Beloved" pays tribute to South Korea’s democratic struggles.