Y:SY
January 22, 2000 — Seoul, South Korea
Lee Seo-yeon, known professionally as Y:SY, is a South Korean singer-songwriter and rapper under H1GHR Music. She is a former member of the girl group fromis_9, formed through the reality survival show Idol School (2017). She left the group in 2024.
She made her solo debut on November 17, 2025, with the digital single Naked.
