Idol School was a South Korean reality show that aired on Mnet in 2017. The show featured 41 female trainees from various entertainment companies competing to debut in a new girl group. The final lineup consisted of nine members: Natty, Somi, Kyulkyung, Pinky, Elly, Nagyung, Kaeun, Chaeyoung, and Jiwon. The group debuted in July 2017 with the song "To Heart." Idol School disbanded in January 2019.