IU (singer)
Park Jae-chan, also known mononymously as Jaechan, is a South Korean singer, actor, and songwriter. He is a member of the K-pop boy group DKZ and was a member of its sub-unit Dongkiz I:Kan. As an actor, he is best known for his portrayal of Choo Sang-woo in the web novel-adapted drama series Semantic Error. Wikipedia