Kim Se-jeong

In June 2018, a Gugudan subgroup named Gugudan Semina was formed with Sejeong and members Mina and Nayoung. They debuted on July 10, 2018. In September 2018, Sejeong released the song "Lover" for the OST of the Korean drama Mr. Sunshine. After a year of hiatus as a singer, on December 2, 2019, Kim released the single "Tunnel" with Dingo Music, followed by her first EP "Plant" (Korean: 화분 ; RR: Hwabun), with its lead single of the same name, released on March 17, 2020.

On January 12, 2017, Kim released the song "If Only" for the OST of the Korean drama The Legend of the Blue Sea. That month, she became a permanent MC for OnStyle's Get It Beauty. In July 2017, she took on her first major acting role as the lead, Ra Eun-ho, in KBS2's teen drama School 2017. Later that year, she sang "Star Blossom" for SM Station with NCT's Doyoung. In September 2017, It was confirmed that Kim will be a fixed cast member in Netflix's variety show Busted!.

In January 2016, she represented Jellyfish Entertainment together with fellow trainees Kim Na-young and Kang Mi-na on the reality survival show Produce 101 for the chance to debut in a Mnet girl group. All three were assigned to "Group A" in the first episode of the program, and she achieved the first-place ranking on several episodes, earning the nickname "God Sejeong". The program came to an end on April 1, 2016, and the final line-up of I.O.I, made up of the top 11 poll-winners, was announced. Kim finished second overall, with 525,352 votes, becoming an official member of the girl group. I.O.I promoted as a whole for events and advertising gigs.

Plans for Kim to host a new KBS show Talents for Sale alongside Kim Jong-kook, Lee Seo-jin and Noh Hong-chul were announced in April 2016. She displayed a variety of talents on the show and earned the nickname 'Variety Cheat Key'. On June 10, 2016, YMC Entertainment revealed that Kim would not be taking part in I.O.I's unit promotions but would instead return to her agency to debut and promote with its upcoming girl group. On June 28, 2016, Kim officially debuted as a member of South Korean girl group Gugudan. On November 23, 2016, Kim participated in Jellyfish Entertainment’s music channel project Jelly Box and released the single "Flower Way" (Korean: 꽃길 ; RR: Kkotgil), produced by Zico, along with a music video. The single topped seven major charts upon its release, and Kim received her first music program trophy as a solo artist with "Flower Way" on the November 30th episode of Show Champion.

In 2012, Kim participated in the second season of competition television show K-pop Star 2 at the age of 16. She did not make it through the second round ranking audition, but Yang Hyun-suk brought her back as a wildcard for the casting round, where she performed a duet of Taeyang's "I Need A Girl" with fellow contestant Jo Yoo-min. Yang cast the both of them, grouping Kim with contestants Nicole Curry and Lee Soo-kyung for the final casting round. However, at the end of the round, she was eliminated from the competition.

Kim Se-jeong (born August 28, 1996), better known by the mononym Sejeong, is a South Korean singer and actress signed under Jellyfish Entertainment. She is best known as the runner-up contestant in Produce 101, a former member of the girl group I.O.I, and as a member of Gugudan and its subgroup Gugudan Semina. She was a co-host of the variety show Talents for Sale in 2016 and played the leading role in the teen drama, School 2017.