Kep1er (케플러) (also stylized as Kepler) is a 9 member K-pop project girl group formed through the Mnet survival show Girls Planet 999. The group consists of Yujin, Mashiro, Xiaoting, Chaehyun, Dayeon, Hikaru, Huening Bahiyyih, Youngeun, and Yeseo. The final lineup was announced on October 22, 2021, during the final episode of Girls Planet 999. The group is managed by WAKEONE Entertainment and Swing Entertainment. They will promote for 2 years and 6 months starting on their debut date.