C9 Entertainment's upcoming new boy group C9Rookies has revealed their 4th member, MU!

MU, whose stage name is pronounced "Miu", was born on September 14, 2003. He's 184 cm and 63 kg and joins the C9Rookies lineup along with members Keum Dong Hyun, Baek Seung, and A-Min, who were introduced earlier this week. 

Check out MU's pre-debut profile film below.