Three units were revealed so far.
LOONA 1/3 is the first unit, with four official members, and one unofficial member. They live on earth, and form the structure for the rest of the LOONAVERSE.
ODD EYE CIRCLE
ODD EYE CIRCLE is made up of three current members and one former member. They are between light and darkness, and therefore interact with both. They live in the middle earth.
yyxy are the mirror image to LOONA 1/3. They represent the darkness in the LOONAVERSE and tell the story of Adam and Eve, with each member eating their representative fruits and being outcasted by the rest of LOONA. They represent youth and the naivety and boldness of youth.