Prior to his debut under RealCollabo, Jooyoung and his schoolmate Shin Dong-woo (who later debuted as B1A4's CNU) created a J&D duo for 2009 Chinchin Youth Song Festival.
Sebelum debut di bawah RealCollabo, Jooyoung dan teman SMAnya Shin Dong-woo (yang kemudian debut sebagai CNU dari B1A4) membentuk duo J&D untuk 2009 Chinchin Youth Song Festival.