Chu So-jung (Korean: 추소정; born November 6, 1995), better known by her stage name Exy, is a South Korean rapper, singer and songwriter. She debuted as a member and leader of South Korean girl group WJSN formed under Starship and Yuehua in 2016. Chu So-jung (Korean: 추소정; born November 6, 1995), better known by her stage name Exy, is a South Korean rapper, singer and songwriter. She debuted as a member and leader of South Korean girl group WJSN formed under Starship and Yuehua in 2016.