Kep1er is a South Korean girl group formed through the Mnet reality survival competition show Girls Planet 999 in 2021 and managed by Swing Entertainment and Wake One Entertainment. The group is composed of nine members: Kim Chae-hyun, Huening Bahiyyih, Choi Yu-jin, Kim Da-yeon, Seo Young-eun, Kang Ye-seo, Hikaru Ezaki, Mashiro Sakamoto, and Shen Xiaoting. They made their official debut on January 3, 2022, with the extended play (EP) First Impact.