Yun Seo-young, known professionally as YSY, is a South Korean rapper-songwriter and dancer under Chapter-I. She is the leader of the girl group H//PE Princess, formed through the 2025 survival show Unpretty Rapstar: HIP POP Princess, and a former pre-debut member of the girl group VVS. She made her solo debut on June 25, 2024, with the collaboration single "Love Me No More (Remix)".

윤서영 , Yun Seo-young , ユン・ソヨン , Yoon Seo-young , H//PE Princess , HIIPE Princess