Sejeong/ Kim Sejeong (ex. gugudan)

Who is Kim Sejeong?

Kim Sejeong is a South Korean singer and actress born on August 28, 1996, in Gimje, North Jeolla Province. She gained national recognition after finishing second in Mnet's survival show Produce 101, which led to her debut as a member of the project girl group I.O.I. Following her success with I.O.I, she became a member of Jellyfish Entertainment's girl group Gugudan, where she served as the main vocalist and face of the group.

Her career trajectory expanded beyond music into acting, where she established herself through lead roles in several television series. Specifically, she starred in School 2017 (2017), The Uncanny Counter (2020-2023), Business Proposal (2022), and Brewing Love (2024). These drama roles solidified her position as both a recording artist and television actress in the South Korean entertainment industry.

Kim Sejeong debuted with I.O.I on May 4, 2016, with their first mini album "Chrysalis". Subsequently, she debuted with Gugudan on June 28, 2016, with their first mini album "Act.1 The Little Mermaid". She launched her solo career on November 23, 2016, with the digital single "Jelly Box Flower Way". After I.O.I officially disbanded on January 29, 2017, she continued activities with Gugudan until the group disbanded on December 31, 2020.

Her management history reflects significant career transitions. After spending 10 years with Jellyfish Entertainment, she joined BH Entertainment on March 24, 2026. This move marked a new phase in her career as she continued pursuing both solo music activities and acting projects.

Kim Sejeong stands 164 cm tall with blood type AB. She studied practical music at Hanyang Women's University. Her versatility spans multiple entertainment sectors, including variety show hosting, where she served as MC for programs such as Talents for Sale and Get It Beauty. Her acting debut came in July 2017 with KBS2's teen drama School 2017, establishing her dual career path. She also participated in the sub-unit Gugudan SEMINA, which released their first single album "Semina" in July 2018.

Kim Sejeong's childhood and early beginnings

Family background and upbringing

Her parents separated during her childhood, resulting in her mother raising both her and her older brother as a single parent. The family relocated from Gimje to Anyang, Gyeonggi Province, where they resided at her aunt's residence. Their living conditions reflected significant financial constraints, occupying approximately 40 square meters of space.

Her mother worked multiple positions to support the family, including milk delivery and tutoring, before transitioning to accounting at the age of 40. These economic difficulties manifested in her school experience, where she required a subsidized lunch card designated for students unable to afford meals. She maintained no contact with her father until reaching her third year of middle school, marking a 10-year separation.

Prior to pursuing entertainment, she participated in track and field competitions during elementary and middle school, subsequently joining the Theatre Club during her high school years. Her aspiration to become a singer prompted auditions at over 20 agencies, including SM Entertainment. She initially expressed reluctance to discuss her musical ambitions with her mother due to concerns about financial obligations and potential failure. Her mother's response, advising her to pursue her chosen path without concern for parental considerations, became the catalyst for her entertainment career.

Training at Jellyfish Entertainment

She successfully passed Jellyfish Entertainment's audition process, competing against approximately 3,000 applicants in a highly selective 3,000 to 1 ratio. This achievement secured her position as a trainee at the agency, where she underwent approximately two years of training before participating in Produce 101.

K-Pop Star 2 competition

At 16 years old, she entered the second season of K-pop Star 2 in 2012. Her initial performance did not advance her beyond the second round of the ranking audition. Yang Hyun-suk, then CEO of YG Entertainment, selected her as a wildcard entry for the casting round. During this opportunity, she performed a duet rendition of Taeyang's "I Need A Girl" with contestant Jo Yoo-min. Both advanced to the final casting round alongside Nicole Curry and Lee Soo-kyung, where she ultimately faced elimination from the competition.

Rise to fame with Produce 101 and I.O.I

Produce 101 journey

In January 2016, she represented Jellyfish Entertainment on the reality survival show Produce 101 alongside fellow trainees Kim Na-young and Kang Mi-na for the opportunity to debut in an Mnet project girl group. She initially turned down the offer to participate, as she was already scheduled to debut with Jellyfish Entertainment's girl group Gugudan. The show presented significant challenges, with cameras positioned throughout the facility. She experienced difficulty practicing freely due to concerns about being judged through constant surveillance, fearing observers might criticize her efforts as performative.

All three Jellyfish trainees received A grades during the initial class assignment and were placed in Class A, the highest tier. She achieved first-place ranking on several episodes throughout the competition. Her performances included leading the group battle evaluation with Wonder Girls' "Irony," where she provided individual instruction to fellow contestant Kim So-hye, earning the designation "Sejeong sensei". For the position evaluation, she selected vocal as her category and performed Zion.T's "Yanghwa Bridge," securing first place in the vocal evaluation and gaining 100,000 additional votes.

Her emotional moment during the first elimination round produced lasting cultural impact. After securing first place, she delivered a speech to her mother stating, "I will only let you walk on the flower road from now on," which established her as the icon of "Flower Way" through broadcasts and media. She finished as the runner-up contestant of the season, garnering 525,352 votes, maintaining second place except for one instance throughout the program. She competed directly with Jeon So-mi, who secured first place, with the two maintaining a rivalry for six months while competing for weekly rankings.

I.O.I debut and activities

I.O.I officially debuted on May 4, 2016, with the lead single "Dream Girls" from the album Chrysalis. The group comprised eleven members selected from 101 trainees representing various entertainment companies. The debut, originally planned for April 1, 2016, with the song "Crush" from the finale performance, was postponed to refine the group's concept and choreography.

Following their debut showcase at Jangchung Gymnasium in Seoul on May 5, the group performed on Mnet's M Countdown. I.O.I released their extended play Miss Me? on October 17, 2016, with the title track "Very Very Very" composed by Park Jin-young. The group received their first music program trophy with this song on Show Champion on October 26. YMC Entertainment confirmed the group's disbandment on November 5, 2016, with activities concluding on January 31, 2017. The final concert, Time Slip – I.O.I, took place from January 20 to 22, 2017, at Jangchung Gymnasium.

Impact on her career

She served as vocalist for I.O.I, recognized for her sweet, powerful, raspy voice and emotionally healing songs. Her singing style drew influence from role models IU, Girls' Generation's Taeyeon, and Ailee. The group marked her official debut in 2016, establishing the foundation for her subsequent career trajectory. Regarding the group's 10th anniversary in 2026, she indicated plans for a meeting to develop commemorative activities, expressing intentions to provide gifts for waiting fans.

Kim Sejeong's group activities with Gugudan

Joining Gugudan

On June 10, 2016, YMC Entertainment confirmed her return to Jellyfish Entertainment to join the company's upcoming girl group. While maintaining her commitments as an I.O.I member, she joined Gugudan alongside Kang Mi-na on June 28, 2016, debuting with the lead single "Wonderland" from the mini-album Act.1 The Little Mermaid. This marked Jellyfish Entertainment's first girl group formation, with the group eventually comprising nine members including Mimi, Hana, Haebin, Nayoung, Sally, Soyee, Mina, and Hyeyeon.

Subsequently, she participated in Jellyfish Entertainment's music channel project Jelly Box, releasing the single "Flower Way" on November 23, 2016. Produced by Zico and accompanied by a music video, the single achieved commercial success by peaking at number two on the Gaon Digital Chart. She received her first solo artist music program trophy for this single on the November 30 episode of Show Champion.

Group promotions and releases

Gugudan's promotional activities spanned multiple album releases between 2016 and 2018. Their discography included three mini albums and two single albums. Following their debut, the group released Act.2 Narcissus with the title track "A Girl Like Me" on February 27, 2017. The group continued with Act.3 Chococo Factory on November 8, 2017, followed by Act.4 Cait Sith featuring the lead single "The Boots" on February 1, 2018. Their final release, Act.5 New Action, containing six tracks with the lead single "Not That Type," appeared on November 6, 2018.

Gugudan SEMINA sub-unit

In June 2018, she formed Gugudan SeMiNa with fellow Produce 101 alumni members Mina and Nayoung. The sub-unit name derived from combining the first syllables of the three members' names. Gugudan SeMiNa debuted on July 10, 2018, with their self-titled single album "SEMINA". The title track featured a modern reinterpretation of the Blues genre, incorporating brass instruments and funky bass sounds while showcasing the members' vocal abilities. The album included three tracks: the title song "Semina," "Ruby Heart," and an instrumental version of the title track. This represented Gugudan's second sub-unit following Gugudan 5959, which had released their debut single "Ice Chu" in August 2017.

Kim Sejeong's acting career in drama and TV shows

School 2017 acting debut

Her first major acting role came as Ra Eun-ho in KBS2's teen drama School 2017, which aired in July 2017. The character drew webtoons within the drama narrative, prompting her to consult her cousin who worked in a game company's drawing department for authentic portrayal. She received guidance from his colleagues who created webtoons professionally, incorporating small habits to develop the character. Her performance earned the Best New Actress award at the 31st KBS Drama Awards.

The Uncanny Counter success

In 2020, she portrayed Do Ha-na in The Uncanny Counter, a role based on the webtoon "Kyeongirowoon Somoon". The character possessed abilities to sense evil spirits from hundreds of kilometers away and read memories through touch. The series achieved record-breaking status as the highest-rated OCN series of all time. She contributed the self-written and composed song "Meet Again" to the drama's soundtrack, which charted at 147 on the Gaon Digital chart. Her approach to action sequences involved memorizing movements as choreography, maintaining composure during filming, and continuous practice. She reprised the role in the series' second season during 2023.

Business Proposal and other drama roles

Business Proposal marked her first romantic comedy in February 2022, paired with Ahn Hyo-seop. The SBS series attained the highest viewership ratings at 11.6% for terrestrial Monday-Tuesday dramas in 2022. Her portrayal drew comparisons to Emma Stone, earning the designation "Korea's Emma Stone" for similar acting style and features. She participated in two acting study groups for practice. The series ranked eighth overall in Netflix's Most Popular Non-English Shows for 2022. In 2019, she starred as a timpanist in I Wanna Hear Your Song, winning the K-Drama Hallyu Star Award at the 2019 KBS Drama Awards.

Variety show appearances

She hosted Talents for Sale alongside Kim Jong-kook, Lee Seo-jin, and Noh Hong-chul in 2016, receiving a Rookie Variety nomination at the 15th KBS Entertainment Awards. In September 2017, she joined Netflix's first Korean variety show Busted!, appearing across three seasons through 2021.

Solo music career and personal life

Solo debut and releases

Following her November 2016 debut single "Flower Way," she released her first self-written and composed extended play titled "Plant" on March 17, 2020. The EP marked her second music award show trophy on The Show for the lead single. Subsequently, she released her second EP "I'm" on March 29, 2021, with the lead single "Warning," both written and composed by her.

Her first full-length album "Door" appeared on September 4, 2023, containing 11 tracks with two lead singles "Voyage" and "Top or Cliff". She wrote all 11 tracks and composed eight of them. The album preparation spanned three years, with full production beginning one year before release. She embarked on her first solo concert tour "The Door" across 11 cities internationally, including Korea, Japan, Taiwan, Singapore, Malaysia, and Australia. In 2026, she returned with the single "Solar System" after a hiatus of two years and three months. Her agency transition occurred when she departed Jellyfish Entertainment on March 23, 2026, joining BH Entertainment on March 24.

Musical theater work

She made her musical debut in "Return: The Promise of the Day," an original army musical addressing Korean War remains excavation. From June 7 to August 24, 2021, she performed in "Red Book," a feminist Victorian-era musical, as protagonist Anna for 28 shows. The production achieved a 9.9 out of 10 viewer rating, ranking highest among 2021's top 20 musicals, and received the Best Picture Award. She earned a Best New Musical Actress nomination at the 2022 Korean Musical Awards. She later starred in the play "Temple" as Temple Grandin, a character with autism who became a world-renowned animal behaviorist.

Personal interests and philanthropy

She donated ₩50 million to the Autism Society of Korea following her role in "Temple". Her 2022 contributions included ₩10 million to Hope Bridge for Uljin wildfire victims, ₩10 million to Fruit of Love for Ukraine war refugees, ₩20 million for South Korean flood relief, and ₩10 million for Typhoon Hinnamnor victims. In 2023, she donated ₩40 million to support Turkey-Syria earthquake victims. Her personal interests include composing, writing lyrics, traveling with loved ones, and exploring culinary experiences.

FAQs

Her current professional focus centers on the romantic drama Brewing Love, alongside various endorsement contracts and musical projects. Regarding language abilities, she demonstrates proficiency in four languages: Korean, Chinese, Japanese, and English. Financial reports estimate her net worth between 5 and 7 million USD.

She gained recognition for her creative responses during promotional interviews. When asked how to pass a camel through a needle hole, she replied that one simply needs to view the camel through the needle hole. Similarly, when questioned about finding a needle in a desert, she suggested naming a rock "needle". In a previous GQ Magazine interview, she addressed how long it would take to move Hallasan mountain to Seoul, answering it requires only one day by changing Jejudo's administrative district to Seoul.

On workplace relationships, she stated she would not date a coworker, citing her inability to maintain secrecy. She described herself as a terrible liar whose emotions are visible on her face, making workplace romance impractical. Her approach reflects the challenges of maintaining privacy within the entertainment industry, where discretion regarding personal relationships remains paramount.