ArtistChoi Creative Lab
Seoi
Lee Ye-jin, known as Seoi (서이), is the leader and lead vocalist of H1-KEY under Choi Creative Lab. Born on February 12, 2000 in Seongnam, Gyeonggi Province, South Korea, Seoi is the oldest member and was the second to be revealed during pre-debut activities in November 2021.
Before joining H1-KEY, Seoi trained for three years at YG Entertainment as a member of YG Trainee Team 2, forming close friendships with Purple Kiss member Chaein and Billlie member Moon Sua. Her drive to become an idol crystallised after watching SNSD perform "Gee" on television with her mother, a moment she credits as transformative.
Standing 168 cm tall with an ESTJ personality, Seoi brings focused, grounded leadership to H1-KEY. Her role models include actress Son Yejin, HyunA, and Little Mix. She has expressed ambitions to venture into acting alongside her music career. Her personal motto: "Seeing the bright side will brighten up my life."
Seoi has contributed to every H1-KEY release since their January 2022 debut with Athletic Girl, through Rose Blossom, Seoul Dreaming, Love or Hate, Lovestruck, and the 2026 EP Lovechapter.
1 articles7 creditsDebut: January 5, 2022Korean
Gallery
Seoi at H1-KEY Seoul Fashion Week, February 2026 (TV10, CC BY 4.0)
Discography
2026
LOVECHAPTERMini Album
Vocalist, Leader
2025
LovestruckMini Album
Vocalist, Leader
2024
Love or HateMini Album
Vocalist, Leader
2023
Seoul DreamingMini Album
Vocalist, Leader
2023
Rose BlossomMini Album
Vocalist, Leader
2023
Seoul (Such a Beautiful City)Single
Vocalist
Other Credits
2022
Athletic GirlSingle Album
Vocalist, Leader
Fans Also Ask
When did Seoi debut?
Seoi debuted as leader of H1-KEY on January 5, 2022, with the group's first single album Athletic Girl under Grandline Group. She was the second member revealed during pre-debut activities, announced November 26, 2021. The group is now managed under the reorganized Choi Creative Lab with Sony Music Korea distribution.
Was Seoi a trainee at YG Entertainment?
Yes. Before H1-KEY, Seoi trained for three years at YG Entertainment as part of YG Trainee Team 2. During that period she formed close friendships with Purple Kiss member Chaein and Billlie member Moon Sua. Her decision to pursue an idol career crystallised after watching SNSD perform Gee on television with her mother.
What is Seoi's role in H1-KEY?
Seoi is the leader and lead vocalist of H1-KEY. As the group's oldest member at 168 cm, she brings focused, grounded leadership to the four-member lineup. Her role models include actress Son Ye-jin and HyunA, and she has expressed ambitions to pursue acting alongside her music career.
What has H1-KEY released?
H1-KEY's discography spans from their 2022 debut single Athletic Girl through Rose Blossom and Seoul Dreaming (2023), Love or Hate (2024), Lovestruck (2025), and the 2026 EP LOVECHAPTER. The group is distributed by Sony Music Korea through Choi Creative Lab and has built a reputation for athletic, performance-forward K-pop.
What are Seoi's personal interests outside of H1-KEY?
Seoi has spoken about ambitions to venture into acting alongside her music career and lists actress Son Ye-jin as a key role model. She also cites HyunA and Little Mix as musical inspirations. Her personal motto is: Seeing the bright side will brighten up my life.
