Sei (Lee Seo-jeong)

Sei (Lee Seo-jeong) Profile

Photo of Sei (Lee Seo-jeong)

Who is Sei (Lee Seo-jeong) ?

Sei (세이), born Lee Seo-jeong (이서정) on January 7, 2000, is a South Korean singer, rapper, and actress best known as a member of the girl group Weki Meki under Fantagio. She gained attention as a contestant on Mnet’s survival show Produce 101 and officially debuted in 2017.

Sei (Lee Seo-jeong) – Biodata

Sei (Lee Seo-jeong) – Biography

Explore the complete biography of Sei from Weki Meki – from her early life, debut, rise in K-pop, to her post-group activities.

Early Life and Education

Sei, born Lee Seo-jeong (이서정) on January 7, 2000, in South Korea—reportedly in either Songpa District or Ansan, Gyeonggi Province—is a South Korean singer, rapper, and actress. From a young age, she displayed strong interests in music and performance. Before her idol debut, she trained under LOUDers Entertainment and later transferred to Fantagio, a well-known K-pop agency. She later enrolled at Baekseok Arts University, focusing on artistic and musical development.

Pre-Debut and Produce 101

In 2016, Sei participated in Mnet’s survival reality show Produce 101, representing LOUDers Entertainment. Although she did not make it into the final debut lineup, her charming visuals and calm demeanor gained her attention. She ranked 85th before being eliminated, but the exposure opened further opportunities.

Debut with Weki Meki

Sei officially debuted as a member of Fantagio’s new girl group Weki Meki on August 8, 2017, with the mini-album WEME. Within the group, she took on roles as lead vocalist and rapper. Weki Meki quickly became known for their youthful energy and powerful concepts. Their hit songs included “I Don’t Like Your Girlfriend,” “La La La,” “Crush,” “Picky Picky,” and “Cool.”

Sei was recognized for her soft voice, subtle charisma, and her contributions to the group’s unique image. Her fanbase grew steadily, especially among those who appreciated her versatility and personality.

Group Activities and Growth

Over the years, Weki Meki released a series of mini-albums and digital singles, solidifying their place in the competitive K-pop industry. Sei also began to explore acting, slowly transitioning into roles in web dramas and collaborative projects while staying active with group promotions.

In addition to singing and dancing, Sei showed interest in songwriting and playing the guitar, often sharing clips and behind-the-scenes moments with fans through social media.

Acting Career and Solo Projects

After several years with Weki Meki, Sei expanded her activities to include acting. She made appearances in web series such as Cheongchunhyang Jeon (2021) and Our Love Triangle (2024), where her natural acting style was well received. She also participated in musical collaborations, including “Tonight” by Ants.

Weki Meki Disbandment and New Chapter

In June 2024, after nearly seven years of group activity, Weki Meki officially disbanded as all members, including Sei, chose not to renew their contracts with Fantagio. Sei expressed gratitude toward fans and began preparing for a new chapter of her career—focusing on acting, solo music, and potential variety appearances.

Legacy and Public Image

Sei is admired for her intelligence, quiet strength, and graceful charm. Her fans describe her as introspective, sincere, and artistically inclined. With her INFJ personality, she often supports those around her and brings calm to energetic settings. As she continues her journey in the Korean entertainment industry, fans remain hopeful and excited for what’s next.

Sei (Lee Seo-jeong) – Discography

Discover the complete discography of Sei from Weki Meki, including group albums, singles, and collaborations throughout her K-pop career.

With Weki Meki – Mini Albums

• 2017: WEME – Debut mini-album featuring “I Don’t Like Your Girlfriend”
• 2018: Lucky – Includes the title track “La La La”
• 2019: LOCK END LOL – Featuring “Picky Picky”
• 2019: Week End LOL – Repackage album with “Tiki-Taka (99%)”
• 2020: HIDE and SEEK – Featuring “Oopsy”
• 2020: NEW RULES – Includes “Cool”
• 2021: I AM ME. – Featuring “Siesta”

Digital Singles with Weki Meki

• 2018: Butterfly – Asian Games supporting single
• 2021: Sweet Dreams – Part of Fantagio winter project
• 2022: DAZZLE DAZZLE

Collaboration Songs

• 2023: Tonight – with Ants (Digital Single)
• 2021: Starry Night – Weki Meki X UNIVERSE Music

Soundtrack Appearances

• 2024: Love Out Loud OST – “Confession Day” (unofficial listing; web drama theme)

Compilation Appearances

• 2018–2023: Featured in several Fantagio family releases and seasonal tracks

Sei (Lee Seo-jeong) – Filmography

Explore the complete filmography of Sei from Weki Meki, including her roles in web dramas, variety shows, and other television appearances.

Web Dramas

• 2021: Cheongchunhyang Jeon – Lead Role
• 2024: Our Love Triangle (우리의 삼각 로맨스) – Main Cast

Variety Shows & Appearances

• 2016: Produce 101 (Season 1) – Contestant (Ranked 85th)
• 2017–2021: Weekly Idol – Guest (as Weki Meki)
• 2018: Idol Room – Guest
• 2020: Pops in Seoul (Arirang TV) – Interviewee (with Weki Meki)
• 2022: Fact iN Star – Guest Appearance

Music Show Performances (with Weki Meki)

• 2017–2021: M Countdown, Inkigayo, Music Bank, Show Champion – Performed title tracks and comebacks

Special & Online Content

• 2021: Dingo K-Drama Parody Series – Skits with Weki Meki
• 2019–2023: Weki Meki Mohae? (Web Reality Show)

Sei (Lee Seo-jeong) – Awards & Achievement

See the complete list of awards, nominations, and achievements Sei from Weki Meki has earned throughout her K-pop and acting career.

Group Achievements with Weki Meki

• 2017: Best Rookie Girl Group – 1st V Live Awards
• 2017: New Wave Award – Asia Artist Awards
• 2018: Rising Star Award – Soribada Best K-Music Awards (with Weki Meki)
• 2018–2021: Regular nominations on Show Champion, Inkigayo, M Countdown, and Music Bank
• 2020: Top 10 K-pop Girl Groups – Ranked by Korean news outlets (Weki Meki)

Music & Industry Milestones

• 2017: WEME mini-album surpassed 47,000 copies in sales — highest for debuting girl group that year
• 2019: LOCK END LOL and “Picky Picky” ranked on Gaon and Billboard Korea charts
• 2020: “Cool” performance recognized for viral choreography and concept transformation
• 2021: I AM ME. featured in top 50 girl group albums by Korean critics

Individual Recognition

• 2021: Most Promising Idol Actress (Web Drama) – K-Content Critics Poll
• 2024: Positive reviews for lead role in Our Love Triangle web drama
• 2023: Recognized for vocals in collaboration track “Tonight” with Ants

Career Highlights

• Debuted in Weki Meki under Fantagio on August 8, 2017
• Competed in Produce 101 (Season 1) in 2016
• Participated in major K-pop festivals: KCON, SBS Super Concert, and Dream Concert (2017–2020)
• Completed 7 years of group promotions before Weki Meki’s disbandment in 2024
• Transitioned into acting and solo performance successfully post-2024

Interesting & Fun Facts About Sei (Lee Seo-jeong)

Explore fun and interesting facts about Sei from Weki Meki. Learn more about her personality, pre-debut life, habits, and unique traits.

• Her real name is Lee Seo-jeong (이서정), and she was born on January 7, 2000.
• She appeared on Mnet’s “Produce 101” in 2016 and ranked 85th before elimination.
• Her stage name “Sei” means “six” in Italian, because she was the sixth Weki Meki member to be revealed.
• She was originally a trainee under LOUDers Entertainment before joining Fantagio.
• Sei debuted with Weki Meki on August 8, 2017, with the mini-album WEME.
• Her official positions in the group were lead vocalist and rapper.
• She’s known for her calm, intelligent, and reserved personality, often described as elegant by fans and members.
• Her MBTI type is INFJ, which suits her introspective and thoughtful nature.
• She’s a vegetarian and is very conscious about health and animal welfare.
• She enjoys playing guitar, writing lyrics, composing songs, and sketching in her free time.
• She attended Baekseok Arts University to pursue her passion for music and performance arts.
• She starred in the web dramas Cheongchunhyang Jeon (2021) and Our Love Triangle (2024).
• After Weki Meki disbanded in 2024, Sei did not renew her contract with Fantagio and began pursuing solo and acting projects.
• She featured in the 2023 digital single “Tonight” by Ants.
• Her nickname among fans is Seiric, derived from her Instagram handle @seiric_o.
• She’s left-handed and said to be very neat and organized in her daily habits.
• Her favorite colors are light pink and pastel tones.
• She loves animals, especially cats, and hopes to adopt one in the future.
• Among fans, she’s known for her soft smile and gentle stage presence.
• She has a subtle yet witty sense of humor that shines in variety shows and fan interactions.

Sei (Lee Seo-jeong) – Social Media Accounts

Find all of Sei’s official social media accounts, including Instagram and Weki Meki profiles.

• Personal Instagram: @seiric_o
• Weki Meki Group Instagram (Archived): @weki_meki
• Weki Meki Official Twitter (Group): @WekiMeki
• Fantagio Music Official YouTube (MV & Content): youtube . com/c/FantagioMusic