After dropping out of Dongguk University he joined a hip-hop crew known as Diamond Tribe with members: JuNi, Freestarr, LEGO, and Marco and Lugar of Mo'Real, who performed frequently at Club Belly in Apgujeong-dong.
[3] His activities began to gain more attention when he joined the music group, Romantic City and produced lyrics under the name Rocy.
[5] In early 2010 J'Kyun announced that he had signed with BigDeal Records, where he went on to release his first studio album Re Birthday in May of the same year.
[7] In October J'Kyun announced that he had decided to leave Bigdeal Records, and that he was involved in a project with vocalist Kuan, currently preparing an underground EP.
[10] In April 2012, J'Kyun released his second extended play These Days including the single "Hot MC" featuring Zico of Block B, the EP peaked at number 70 on the Gaon Chart.