Park Jae-hyung (Korean: 박제형; born September 15, 1992), better known as Jae (Korean: 제이), is an American musician, singer, songwriter, and composer of Korean descent, best known as a former vocalist and lead guitarist of South Korean rock band Day6. Prior to joining Day6, he gained attention in South Korea as one of the final six contestants in the first season of the singing competition television series K-pop Star. In 2020, Park began releasing solo music under the name eaJ.