Born and raised in Seoul, South Korea, Choi Seung-hyun became interested in hip hop at a young age. He and fellow future Big Bang member G-Dragon were "neighborhood friend[s] from middle school" and often danced and rapped together. Although G-Dragon later moved away and the two "became distant", Choi was contacted by G-Dragon when YG Entertainment, G-Dragon's record label, was scouting for possible candidates to create a boy band. By then, Choi had already performed on many underground stages at hip hop clubs and established a reputation as an underground rapper with the stage name Tempo. He subsequently recorded several demos with G-Dragon and sent them to Yang Hyun-suk, CEO of YG Entertainment, who later asked Choi to audition. Choi was initially rejected by the record label, which deemed him too "chubby" to fit the "idealistic version" of an idol. He later "went home and exercised really hard because I wanted to join YG Entertainment," losing 20 kg in 40 days. Six months later, Choi returned for another audition and was signed.