Loona (stylized as LOOΠΔ) is a South Korean girl group formed by Blockberry Creative. Its twelve members were revealed in a periodic fashion, corresponding to their Korean name Idarui Sonyeo (이달의 소녀), which translates to “Girl of the Month”.

Loona commenced their pre-debut project in August 2016, with each member releasing a promotional single over the next eighteen months. The group has formed three sub-units: Loona 1/3, Loona Odd Eye Circle and Loona yyxy. Their debut EP as a full ensemble, (2018), was supported by the lead single “Hi High”.

Loona’s English name is derived from the Hangul letters ㅇㄷㅇㅅㄴ, each an initial consonant in the syllabic blocks that make 이달의 소녀 (Idarui Sonyeo). When rearranged to ㄴㅇㅇㄷㅅ, it resembles LOONA in the Latin alphabet.

On October 2, 2016, Blockberry Creative announced through Naver that they would be debuting their first girl group through an 18-month long pre-debut project. Between October 2016 and January 2017, four members (HeeJin, HyunJin, HaSeul, and YeoJin) were revealed; each member released a single album typically consisting of a solo track and another track performed with other revealed members, under the group’s Korean name Idarui Sonyeo (Hangul: 이달의 소녀; lit. Girl of the Month) In March 2017, the group’s first sub-unit, Loona 1/3, was introduced, consisting of previously revealed members HeeJin, HyunJin, HaSeul and a new member, ViVi. Loona 1/3 released the extended play Love & Live and accompanying single of the same name on March 13, 2017, with a television promotion on SBS’s Inkigayo, They released a repackaged edition of the extended play, titled Love & Evil, on April 27.

Between April 2017 and July 2017, members ViVi, Kim Lip, JinSoul, and Choerry released their single albums, continuing the same Girl of the Month pattern. In September 2017, three members, HeeJin, HyunJin and HaSeul, auditioned for JTBC’s reality show Mix Nine; HeeJin and HyunJin passed the audition stage making it onto the show, where HyunJin placed Top 18 and HeeJin placed fourth in the finale. The group’s second sub-unit, Loona Odd Eye Circle, consisting of JinSoul, Kim Lip and Choerry, released the extended play Mix & Match on September 21, 2017, and began promotions on Mnet’s M Countdown. The English version of their song “Loonatic” was released on October 23. On October 31 they released a repackaged edition of the extended play, titled Max & Match, which included three new songs.

Between the months of November 2017 and January 2018, they released the solo single albums for new members Yves, Chuu, and Go Won, continuing the monthly pattern. In March 2018, they released the solo single album for final member, Olivia Hye. On May 30, 2018, the group’s third sub-unit, Loona yyxy, made their debut with the extended play Beauty & the Beat. The single “love4eva” featuring Canadian musician Grimes was released the same day with an accompanying music video.

On August 7, 2018, Loona released “Favorite” as the lead single from (read as plus plus), their debut extended play as a full group. The extended play was released on August 20, 2018 alongside the second single, “Hi High”. was repackaged as on February 19, 2019, with six additional tracks, including a new single, “Butterfly”.

Source: wikipedia