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 School to form a new girl group.
Pada Maret 2017, diumumkan bahwa Mnet, produser acara yang sama termasuk Sixteen dan Produce 101, akan merilis acara realitas survival berjudul Idol School untuk membentuk girlband baru.