LOONA is a twelve-member girl group formed by Blockberry Creative. The twelve members were revealed one-by-one each month since October 2016. The group has formed three sub-units: Loona 1/3, Loona Odd Eye Circle, and Loona yyxy. The members are HeeJin, HyunJin, HaSeul, YeoJin, ViVi, Kim Lip, JinSoul, Choerry, Yves, Chuu, Go Won, Olivia Hye. On August 7, 2018, Loona released "favOriTe" as the lead single from [+ +], their debut EP as a full group. The EP was released on August 20, 2018 along with the second single, "Hi High". [+ +] was repackaged as [X X] on February 19, 2019, with six additional tracks, including a new single, "Butterfly". On May 31, 2019, LOONA excited fans with the release of a teaser video “La Maison LOONA,” hinting at a comeback with ballad tracks.