Kim Se Yoon, known professionally as Wow, is a South Korean singer, dancer and member of A.C.E (에이스). Before debuting, he spent some time as a trainee at YG Entertainment. He is the older brother of former trainee Kim Eun Suh. He made his debut in May 2017 as A.C.E's main dancer, vocalist and rapper with their first single album, "Cactus". The group enjoyed initial success thanks to the agency's idea of going busking in Hongdae while covering well-known songs. In April 2021, Beat Interactive (비트 인터렉티브) announced he was experiencing depression and anxiety, so he went on hiatus for a few months. He briefly returned before entering the military. He enlisted for his mandatory military service on September 10, 2021, and was discharged on June 9, 2023. A.C.E’s exclusive contracts with Beat Interactive came to an end on March 31, 2025.