Loona (stylized LOOΠΔ) is a South Korean girl group formed by BlockBerry Creative. They officially debuted on August 19, 2018.

Starting in October 2016, members and sub-units were introduced with music videos and EPs released over the course of 18 months.

The group’s revealed sub-units are the following:

1) LOOΠΔ 1/3, consisting of the three first girls, HeeJin, HyunJin and HaSeul, making up the ‘3’, the fourth girl, YeoJin making up the ‘/‘, and fifth girl Vivi making up the '1’. They released Love & Live in March 2017, which deals with the themes of first love. The following month, they released Love & Evil, which deals with themes of experiencing first heartbreak.

2) LOOΠΔ / ODD EYE CIRCLE is comprised of members Kim Lip, JinSoul and Choerry. Their album Mix & Match was released in September 2017, and its repackage Max & Match the next month. The concept showcased was a girl crush, with the main theme being to not wait for love, but actively look for it and take initiative.

3) LOOΠΔ yyxy is composed of members Yves, Chuu, Go Won and Olivia Hye in the last known sub-unit. They released the album beauty&thebeat in May 2018, which featured the lead single “love4eva”, a collaboration with Canadian singer Grimes.