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구구단

Girl group · Jellyfish Entertainment · since 2016· 3rd generation

gugudan

구구단

Jellyfish's first girl group staged each release as a play, from The Little Mermaid to Puss in Boots, and two members also sang in I.O.I. They disbanded on 31 December 2020.

11years on 28 June 2027 · in 227 days

gugudan, September 2018
gugudan, September 2018. Photo: Lee Wei Lin, Tammi Tan · CC BY-SA 4.0 · Wikimedia Commons

Their story

Nine girls, one troupe

gugudan was the first girl group Jellyfish Entertainment ever put together. Three of its trainees, Nayoung, Sejeong and Mina, had already been seen on Produce 101, and Sejeong and Mina spent 2016 in I.O.I at the same time. In June the company revealed nine members and a name meant to suggest nine girls with nine different charms. Act. 1 The Little Mermaid came out on 28 June, with "Wonderland" as the title song.

A new play every time

gugudan presented itself as an idol theatre troupe, and each release was a new production. Narcissus borrowed from a Caravaggio painting and filled its video with mirrors and selfies. "Chococo" moved into Willy Wonka's factory, "The Boots" took on Puss in Boots, and "Not That Type" was inspired by the heist film Ocean's 8. The concept gave fans a reason to guess at the next chapter.

Units and a smaller stage

Between the acts the members split into units. Mina and Hyeyeon released the summery "Ice Chu" as gugudan 5959 in 2017, and in 2018 Sejeong, Mina and Nayoung tried a funky, blues-based sound as SeMiNa. A Japanese debut followed that September. In October 2018 Hyeyeon left the group. The remaining eight released Act. 5 New Action in November, which turned out to be their last group release.

After the curtain

Two quiet years followed. On 30 December 2020 Jellyfish announced that gugudan would end its activities the next day, and leader Hana thanked the Danjjak in a handwritten letter. In April 2021 Mimi, Soyee and Nayoung left the agency. Sejeong kept up her solo work with the EPs Plant and I'm, and Sally had joined China's BonBon Girls 303 back in 2020.

Timeline

  1. Nayoung, Sejeong and Mina appear on Produce 101 as Jellyfish trainees.

  2. Debut as nine with the EP Act. 1 The Little Mermaid and "Wonderland".

  3. EP Act. 2 Narcissus, led by "A Girl Like Me".

  4. Mina and Hyeyeon debut as the unit gugudan 5959 with "Ice Chu".

  5. Single album Act. 3 Chococo Factory, inspired by Charlie and the Chocolate Factory.

  6. Single album Act. 4 Cait Sith, with "The Boots".

  7. Sejeong, Mina and Nayoung debut as the unit gugudan SeMiNa.

  8. Japanese debut with Stand By and a showcase in Tokyo.

  9. Hyeyeon has left the group, and the eight others release Act. 5 New Action and "Not That Type".

  10. gugudan disbands after four and a half years.

  11. 13 November 2026

Start with these 5 songs

  1. WonderlandThe debut song, set in an undersea theatre for the Little Mermaid concept.2016
  2. A Girl Like MeThe Narcissus chapter: mirrors, selfies and a runway.2017
  3. ChococoA sweet Willy Wonka take, made in a chocolate factory.2017
  4. The BootsThe Puss in Boots chapter and a sharper, darker sound.2018
  5. Not That TypeTheir last title track, a cool heist concept inspired by Ocean's 8.2018

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In the Fan Chart

The Fan Chart on The Crowd adds up every fan's top 10. Here is where gugudan stands.

    Add gugudan to your setlist

    For Danjjak

    Mimi

    Name
    Not confirmed yet
    Born
    Not confirmed yet

    Left Jellyfish in April 2021 and told fans in a letter on Instagram.

    HanaLeader

    Name
    Not confirmed yet
    Born
    Not confirmed yet

    Wrote a handwritten farewell letter to the Danjjak after the disbandment news of December 2020.

    Haebin

    Name
    Not confirmed yet
    Born
    Not confirmed yet

    Her August birthday, with Sejeong's and Hyeyeon's, set the theme of the first fan meeting in 2016.

    Nayoung

    Name
    Not confirmed yet
    Born
    Not confirmed yet

    A Jellyfish trainee on Produce 101 and one third of SeMiNa. She left the agency in April 2021.

    Sejeong

    Sejeong

    김세정
    Name
    Kim Se-jeong
    Born
    Not confirmed yet

    Came second on Produce 101, sang in I.O.I and released the solo EPs Plant and I'm.

    Sally

    Name
    Liu Xiening
    Born
    Not confirmed yet

    Finished sixth on China's Produce Camp 2020 and joined the group BonBon Girls 303.

    Soyee

    Name
    Not confirmed yet
    Born
    Not confirmed yet

    Left Jellyfish in April 2021, announcing it on the same day as Mimi.

    Mina

    Mina

    강미나
    Name
    Kang Mi-na
    Born
    Not confirmed yet

    Sang in I.O.I in 2016 and formed the unit gugudan 5959 with Hyeyeon a year later.

    Portraits, cropped from Wikimedia Commons: Sejeong, June 2025: K-POPIT 케이팝잇, CC BY 3.0 · Mina, April 2026: TV10, CC BY 4.0

    Quick answers

    When did gugudan debut?

    On 28 June 2016, with the EP Act. 1 The Little Mermaid and the title track "Wonderland". The showcase was held the same day at Yes24 Live Hall in Seoul.

    Who were the members of gugudan?

    The final line-up was Mimi, Hana (leader), Haebin, Nayoung, Sejeong, Sally, Soyee and Mina. Hyeyeon, one of the original nine, left the group in October 2018.

    What is the gugudan fandom called?

    Danjjak (단짝), Korean for a best friend. Hana addressed her farewell letter of December 2020 to the Danjjak.

    What does the name gugudan mean?

    Jellyfish said it stands for nine girls with nine different charms, a troupe that performs songs full of hopes and dreams. The name came out of a naming contest inside the company.

    Are gugudan still together?

    No. Jellyfish announced on 30 December 2020 that group activities would end the next day, after long talks with the members. Their last group release was Act. 5 New Action in November 2018.

    Know your gugudan?Six K-pop questions a day in the Daily, and a collectible card for every finished set.

    Play the Daily

    Last checked 30 October 2026. Spotted a mistake? Tell us.

    Sources