On September 8, 2017 former Baby V.O.X member Kan Mi-youn confirmed that she will be producing a seven-member girl group named HashTag and will debut in October.

[2] On October 11, the group's debut EP The girl next door was released.

On September 18, 2018 members Dajeong, Seungmin and Subin debuted as the project trio Purple (퍼플) with the digital single Maemmaeya.

[3] The group had a comeback on April 16, 2019 with their 2nd mini album #Aeji #paSsion.

[5] On March 21, 2023, Luk Factory announced the departures of Dajeong and Aeji, and that the group will continue as 5 members.