Fromis 9 (Hangul: 프로미스나인; initialism for From Idol School; stylized as fromis_9) is an upcoming South Korean girl group formed by CJ E&M through the 2017 reality show Idol School on Mnet. The group's name, pronounced as "promise" in Korean, also means "to keep their promise [to viewers] to be the best girl group". It is composed of nine members: Roh Ji-sun, Song Ha-young, Lee Sae-rom, Lee Chae-young, Lee Na-gyung, Park Ji-won, Lee Seo-yeon, Baek Ji-heon and Jang Gyu-ri.
In March 2017, it was announced that Mnet, same producer of shows including Sixteen and Produce 101, would be launching a new reality survival show titled Idol Schoolto form a new girl group. The show premiered on July 13 and ended on September 29, 2017 with Roh Ji-sun, Song Ha-young, Lee Sae-rom, Lee Chae-young, Lee Na-gyung, Park Ji-won, Lee Seo-yeon, Baek Ji-heon and Jang Gyu-ri as the nine members of Fromis. The final line-up was solely decided through live and online votes of viewers. Pledis Entertainment led by CEO Han Sung-soo managed the group's training and debut.Fromis premiered its own reality program on October 19 titled Fromis's Room about continuing path to debut. It followed the format of a simulcast, where it combined pre-recorded materials and replays of Facebook Live broadcasts in their dorm, hence the name. The group's name was later changed to Fromis 9 following the final episode of Fromis's Room on November 23, 2017, with the 9 meaning the nine students who graduated from Idol School.On November 29, Fromis 9 will reveal their pre-debut single titled "Glass Shoes" at the 2017 Mnet Asian Music Awards in Japan.