Acting
Y:SY
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.
Acting
- 2025Duckbap HouseSelf1 ep.
- 2023Jae Joong and Friends1 ep.
- 2022fromis_9's Autumn NightSelf13 ep.
- 2022fromis_9's Summer NightSelf9 ep.
- 2022Lee Mujin ServiceGuest1 ep.
- 2021The Game CaterersSelf3 ep.
- 2020The Silence Of IDOLSelf2 ep.
- 2019We See Winter2 ep.
- 2018Welcome to Heal Inn4 ep.
- 2017Fromis's Room5 ep.
- 2017프롤로그_프로미스의 방 엿보기1 ep.
- 2017Idol SchoolSelf - Contestant11 ep.
Guest appearances
- 2026Duckbap HouseSelf1 ep.
- 2022The Silence Of IDOLSelf2 ep.
- 2024Jae Joong and Friends1 ep.
- 2023Lee Mujin ServiceGuest1 ep.
- 2022The Game CaterersSelf3 ep.
Also known as: 이서연 · 서연 · Lee Seo-yeon · Yi Seo-yeon