Kwak Dong Hyun is a South Korean rocker and musical actor. He graduated from Gyeongjin High School. He was part of the mixed duo group "Soul Harmony" under the stage name One Kill. He has excellent singing ability, especially high-pitched sounds. He gained popularity when he impersonated Kim Kyung Ho in season 1 of "Hidden Singer" and later signed with his agency, Production Lee Hwang, Inc. He has appeared in other singing competition shows such as "Phantom Singer" where he participated alongside members of Duetto and Forte di Quattro. He is also an active musical actor with roles in several musicals such as "Siddhartha" or "We Will Rock You".
(Source: Korean = Namu Wiki || Translation = MyDramaList)
