4TEN is a four-member South Korean girl group under Jungle Entertainment. 4TEN's official members are Hyeji (혜지), Heeo (히오), Yun (윤), and Hyejin (혜진). The group's former members are Tem (탬), Eujin (유진), and Hajeong (하정). The girl group was initially unveiled through M.I.B’s official Facebook page, sharing the news of their sister group’s debut. They debuted on August 26, 2014 with the single "토네이도 (Tornado)". 4TEN returned in 2015 with their follow up single "왜 이래 (Why)".