Girls Planet 999

Girls Planet 999: The Girls Saga (simply referred to as Girls Planet 999) is a South Korean reality competition show created by Mnet. The aim of the competition was to debut a new 9-member K-pop girl group consisting of trainees and idols from China, Japan, and South Korea.

Out of 13,000 applicants, 99 final contestants were selected. These 99 contestants were split equally into three groups; the K-Group, C-Group and the J-Group. In the finale on October 22, 2021, which was broadcast live, the show announced the final 9 members who would debut as Kep1er.