- Korean: 프로미스나인
- Japanese: プロミスナイン
- Debut: January 24th, 2018
- Members: Saerom, Hayoung, Gyuri, Jiwon, Jisun, Seoyeon, Chaeyoung, Nakyung, Jiheon
- Label: Pledis Entertainment
- Korean sales: 428,612 copies sold
- 2018: 73,466 copies sold
- 2019: 66,759 copies sold
- 2020: 55,537 copies sold
- 2021: 81,032 copies sold
- 2022: 151,818 copies sold
- To. HeartFormat: 1st Mini AlbumRelease Date: January 24th, 20181st Day Sales (Hanteo): 1,451 copies sold1st Week Sales (Hanteo): 3,747 copies sold1st Month Sales (Gaon): 13,452 copies soldTotal Sales in South Korea (Gaon): 21,740 copies soldTo. DayFormat: 2nd Mini AlbumRelease Date: June 5th, 20181st Day Sales (Hanteo): 2,283 copies sold1st Week Sales (Hanteo): 6,179 copies sold1st Month Sales (Gaon): 14,642 copies soldTotal Sales in South Korea (Gaon): 20,480 copies soldFrom. 9Format: 1st Single AlbumRelease Date: October 10th, 20181st Day Sales (Hanteo): 6,208 copies sold1st Week Sales (Hanteo): 17,276 copies sold1st Month Sales (Gaon): 30,684 copies soldTotal Sales in South Korea (Gaon): 36,748 copies soldFUN FACTORYFormat: 2nd Single AlbumRelease Date: June 4th, 20191st Day Sales (Hanteo): 7,421 copies sold1st Week Sales (Hanteo): 28,746 copies sold1st Month Sales (Gaon): 54,986 copies soldTotal Sales in South Korea (Gaon): 61,257 copies soldMy Little SocietyFormat: 3rd Mini AlbumRelease Date: September 16th, 20201st Day Sales (Hanteo): 11,076 copies sold1st Week Sales (Hanteo): 31,815 copies sold1st Month Sales (Gaon): 46,376 copies soldTotal Sales in South Korea (Gaon): 55,537 copies sold
Talk & Talk
Format: Special Single Album
Release Date: September 1st, 2021
1st Day Sales (Hanteo): 3,191 copies sold
1st Week Sales (Hanteo): 11,137 copies sold1st Month Sales (Gaon): 23,000 copies sold
Total Sales in South Korea (Gaon): 23,000 copies sold
Midnight Guest
Format: 4th Mini Album
Release Date: January 17th, 2022
1st Day Sales (Hanteo): 49,712 copies sold
1st Week Sales (Hanteo): 104,438 copies sold1st Month Sales (Gaon): 140,003 copies sold
Total Sales in South Korea (Gaon): 147,254 copies sold