As we know from the name LOONA, the group coincides with the moon. LOONA is pronounced the same as the Spanish word Luna, meaning moon. And as we have seen the moon is an important symbol to LOONA. From the official logo showing the phases of the moon to teaser photos to album covers centered around the moon, and even songs such as Eclipse or Satellite. The idea of the universe and space plays heavily into LOONA's concept, with the moon at the center of it.

And as we know the moon is constantly shifting. As the moon rotates around the earth the sun's rays hit the surface of the moon and bounce down to earth, causing the surface of the moon to be visible at night. Due to the rotation of the earth and of the moon and the angle at which the light hits, at times only certain parts of the moon are visible from earth. We call these the phases of the moon. But it is important to note that it takes around 27 days for the moon to make a complete orbit around earth and almost 30 days to complete all of the phases of the moon. This again ties back to LOONA, with the concept of a new girl each month.

Phases of LOONA 1
The Phases of LOONA 2

Theory 1 (also coincides with X1X) Theory 2 (this one is InSaNe)

The Day and Night UnitsEdit

The Day and the Night Units were first theorized during teasers for LOONA's debut, when six of the members' teasers were released at 12am (KST) and six were released at 12pm (KST). This was later confirmed when the photocards for the limited edition B of + + was either of the "Day Unit" or the "Night Unit".

Night Unit (PM)Edit
Day Unit (AM)Edit

As seen based on the teasers, some of the members wear black clothing and some wear white, pointing to the idea of two opposing chess teams, one being the white unit and one being the black unit, or the day and the night.[1][2][3][4][5][6]

The Chess UnitsEdit

First theorized by caskerbox, the chess units are as follows:

The White UnitEdit
The Black UnitEdit

Line & Up UnitsEdit

The Up & Line Units were featured as photocards for X X Limited A. The Units go as follows:

Line UnitEdit
Up UnitEdit


  1. Day & Night Units Tumblr
  2. Day and Night units
  3. Day and Night Units 2
  4. Day and Night Units 3
  5. Day and Night Units 4
  6. Day and Night Units 5


v - e
HeeJinHyunJinHaSeulYeoJinViViKim LipJinSoulChoerryYvesChuuGo WonOlivia Hye
Solo singles
Mini albums
Repackage albums
Digital singles The Carol 2.0favOriTe
Exclusive releases
Concerts LOOΠΔbirth (2018) • LOOΠΔ Concert [LOOΠΔVERSE] (2019)
Other LOOΠΔ x Study Group (2018) • LOOΠΔ Cinema Theory: Up & Line (2018) • LOOΠΔ Premier Greeting: Line & Up (2018) • LOOΠΔ Studio (2018)
Dramas WoomannaDating Class
Shows Insane Quiz Show Season 2The GashinasShows Appearances : BackstagesInterviewsLivestreamsRadio Shows
Covers DanceVocal
Others LOONA TVChoreographyFancamsLive PerformancesMiscellaneous VideosMusic VideosTeasers
Characters HeeJinHyunJinHaSeulYeoJinViViKim LipJinSoulChoerryYvesChuuGo WonOlivia Hye
Locations EarthCosmosEden
Analysis Music Videos ViViDAround YouLet Me InI'll Be ThereThe CarolKiss LaterEveryday I Love YouEveryday I Need YouEclipseSinging in the RainLove Cherry MotionnewHeart AttackOne & OnlyEgoistfavOriTefavOriTeHi HighButterfly
Cinema Theory ViVi Letter to Hong KongSee SawStarlightI Like You More Nowone
Teasers Reveal Teaser (OEC)XIXXIIXXIIIXXIVXone
Other Lore Möbius Strip TheoryThe Color TheoryCultural ReferencesdlrowehtanoolPhases of LOONAMinor theories
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