Sei 세이 is the lead vocal of Weki Meki.
Sei was born Lee Seojeong 이서정 on January 7, 2000, in Ansan, Gyeonggi-do.
She’s a Capricorn. Sei, Elly, and Lucy’s blood type is B. She was born in the Year of the Hare. She’s 163 cm or 5'4" tall.
She used to be a trainee under LOUDers Entertainment. She competed on “Produce 101” and was eliminated from the show in the 5th episode. She appeared in Astro’s music video for “Confession.” She was the second Weki Meki member to be announced.