Kim Se Hyun, known professionally as Dey, is a South Korean singer, dancer and member of YOUNITE (유나이트). He graduated from Seoul Culture High School, and before debuting, he spent a few years as a trainee at Brand New Music (브랜뉴 뮤직). He made his debut in April 2022 as the group's main rapper with their first EP, “Youni-Birth“. (Source: MyDramaList) Watch drama online for free.