The name Kep1er means capture + one. 'Kep' rhymes with 'To keep / Capture' and it represents how the girls were able to grab their dreams. One (1) represents how the members became the one after the survival.

Kep1er 케플러 is a 9-member South Korean girl group formed through the survival show Girls Planet 999. They officially debuted on January 3, 2022, with the mini-album “FIRST IMPACT” and title track “WA DA DA” and will be promoting for 2.5 years under WAKEONE Entertainment's and Swing Entertainment's management.

The members of Kep1er are: Sakamoto Mashiro, Kang Yeseo, Ezaki Hikaru, Seo Youngeun, Choi Yujin, Kim Dayeon, Kim Chaehyun, Shen Xiaoting, and Huening Bahiyyih.