Ji Yun-seo is a South Korean singer and former member of the boy group EVNNE. Known among Chinese fans by the nickname "Cousin" due to being the cousin of TWICE member Im Na-yeon. In 2023, he participated in the first season of the Mnet survival show Boys Planet as a trainee under Yuehua Entertainment. In September of the same year, he officially debuted as a sub-vocalist for the project group EVNNE under Jellyfish Entertainment. Following the group's disbandment in December 2025, he returned to his original agency and subsequently terminated his exclusive contract with Yuehua Entertainment in February 2026.