Hyun Jinseo

On November 22, 2020, Hyun Jinseo was introduced as a third generation member of CoCo under Fancy Factory through a dance cover video while her name was revealed in the group's Instagram bio. On December 7, CoCo released a profile for Jinseo. On June 29, 2021, CoCo announced that their contracts with all the current lineup members were terminated and that they have revamped their SNS accounts to include the 'Coco Mademoiselle' dance team, some of whom will become official members of the next generation of CoCo, hence Jinseo is no longer a member of CoCo.

Since Jinseo joined after the release of their second digital single and graduated without participating in any new music releases, she thus did not have an official debut. On December 7, 2021, Coco Mademoiselle announced that Jinseo had graduated from their dance team and was promoted to the more senior dance team 'The Queens' (TQNZ).