Nine Muses A

Nine Muses A (Hangul: 나인뮤지스A, stylized as 9MUSES A or 9MUSES AMUSE) was the first sub-group of South Korean girl group Nine Muses formed by Star Empire Entertainment in 2016. It was composed of four Nine Muses members: Gyeongree, Hyemi, Sojin and Keumjo. The group released their debut single album "Muses Diary" on August 4, 2016.
History.
2016: Debut with "Muses Diary".
After the departure of members Minha and Euaerin from Nine Muses in June 2016, Star Empire announced that the group will be making a summer comeback with a unit promotion with no further details. In early-July, it was officially announced that the sub-group will consist of four members, revealing member Gyeongree as first official member of the sub-group. The sub-group will be debuting on early-August. 
 On July 21, it was revealed that the full line-up for the sub-group consists of members Gyeongree (Center), Hyemi (Leader), Sojin (Rapper) and Keumjo (Main Vocal), also revealing that the song "Lip 2 Lip" will be their debut song. Nine Muses A is a shortened name for Nine Muses Amuse, meaning that the group will always make others happy and let them have a great time with their performance.
Nine Muses A released their debut single album "Muses Diary" on August 4, 2016.