Members of third-generation girl groups that dominated the late 2010s, such as IZ*ONE and Lovelyz, may soon return to the stage.

On April 19, an Mnet representative cautiously revealed that the casting for the upcoming June broadcast of "Queendom Puzzle" was still in progress, with IZ*ONE's Nako and Hitomi, Momoland's JooE, Lovelyz's Kei, and Laboum's Haein among the names being considered. "Queendom Puzzle" is a variety show that combines existing girl group members or female artists like puzzle pieces to create the ultimate global project girl group. It is part of Mnet's 'Queendom' series.

The commonality among those mentioned for "Queendom Puzzle" casting is that they are third-generation idols who now face difficulties continuing their group activities. Third-generation idols refer to groups that were active from 2014 to the late 2010s. Due to the typical seven-year contract duration for idols, most groups, excluding BLACKPINK and Red Velvet, have gone through a re-contracting period last year or this year. Depending on whether they renewed their contracts, groups may have disbanded, and members may have gone their separate ways.

IZ*ONE, formed by the 12 finalists from the 2018 Korean-Japanese joint survival program Produce 48, was known for its impressive 26 wins on music shows. The group officially ended all activities with the ONE, THE STORY concert on March 14, 2021, and wrapped up project activities on April 29, 2021. Most IZONE members returned to their respective agencies for re-debut, solo careers, or acting, but Japanese members Nako and Hitomi's activities in Korea have yet to be determined.

Momoland, which debuted in 2016, was a high-energy group best known for their hit song "BBoom BBoom" and Tropicana commercials. However, after several members left the group, their exclusive contract with their agency expired in January of this year, ending their group activities. JooE, like the other members, has announced her intentions for a new beginning.

Lovelyz, Woollim Entertainment's first girl group, consisted of eight talented members and was known for pioneering the "innocent concept," as showcased in their hit song "Ah-Choo." The group, which debuted in 2014, saw seven members choose not to renew their contracts with the agency in November 2021, with the exception of Baby Soul. Member Kei has continued her music activities through musicals and drama OSTs after Lovelyz's disbandment.

Laboum, which debuted in the same year as Lovelyz, gained fame for their military promotional activities and the miraculous reverse success of "Journey to Atlantis." In 2021, Laboum signed a contract with Interpark Music Plus to continue their activities, but due to the agency's circumstances, they ended their group activities in August 2022. Member Haein displayed her unwavering determination for stage activities through her appearances on KBS2's "Idol Rebooting Project - The Unit" and Kakao Entertainment's "Girl's Reverse."