Gugudan (Hangul: 구구단), also stylized as gu9udan or gx9, is a South Korean girl group formed in 2016 by Jellyfish Entertainment. They debuted on June 28, 2016, with the mini-album Act. 1 The Little Mermaidand its title track “Wonderland”. The group consists of nine members: Mimi, Hana, Haebin, Nayoung, Sejeong, Sally, Soyee, Mina and Hyeyeon.
In January 2016, Nayoung, Sejeong and Mina were introduced as Jellyfish Entertainment’s first female trainees on the Mnet survival show Produce 101, where 101 female trainees from various companies competed to debut in an 11-member girl group that would promote for a year under YMC Entertainment. After placing 2nd and 9th respectively in the final episode, Sejeong and Mina eventually debuted as members of I.O.I in May 2016.