The group is managed by Apple Monster and DG Entertainment, and consists of seven members: Kei from Lovelyz, Yeeun from CLC, Yeoreum from WJSN, Yeonhee from Rocket Punch, Nana from Wooah, Hwiseo from H1-Key, and Yuki from Purple Kiss.

El7z Up was formed through the reality competition show Queendom Puzzle, which aired from June 13 to August 15, 2023.

The show brought together twenty-eight active female idols to form a supergroup consisting of seven members.

[7] Yeoreum also participated in the second season as part of her group WJSN, where they finished in first place.

[2] The group held their first concert in Japan titled "Piece Up", taking place in Saitama at Omiya Sonic City [ja] on October 22, in Osaka at Grand Cube Osaka on October 24, and in Tokyo at Tachikawa Stage Garden on November 26.