They were formed through a pre-debut project titled "Girl of the Month".
They were the last sub-unit to debut with the pre-debut project, before the group LOONA debuted as a whole.
II. History: Pre-debut
The first member, Yves, was revealed on November 14, 2017. She debuted with her single album ''Yves'' with the title track "New" on November 28.
Being the first introduced out of the last 4 members, the next to be revealed was Chuu. On December 14, at midnight KST, a teaser photo of the latter was revealed with a caption "A mysterious girl is coming''.The next single titled ''Chuu'' was released on December 27, with the title track "Heart Attack.On January 30, 2 weeks later, her single ''Gowon'' was released with the title track "One&Only".
On January 14, 2018, the teaser photo of the third member, Go Won, was revealed with a caption "Your God person puts an apple tree in the middle of a garden and says, do what you like, guys, oh, but don’t eat the apple. Surprise surprise.".
The final member was then hinted at in a teaser, on March 1. A teaser with all the revealed members, along with a dark figure that appears to be the 12th member. It was titled "Cinema Theory: Up & Line.
Their final member, Olivia Hye, was officially revealed with a teaser photo on March 17.
On March 28, a teaser for her title track "Egoist" was revealed as well, which would feature previously revealed member JinSoul.
On March 29, her single ''Olivia Hye'' was released with the title track "Egoist" featuring JinSoul, and the second track featuring Go Won titled "Rosy".
On May 19, a teaser photo was released revealing the title track "Love4eva" and that it would be featuring Grimes.
On May 24, a group photo teaser was released. On May 28, a highlight medley was released for their upcoming EP.
On May 30, their title track along with their EP Beauty & The Beat was released.
IV. MV and Album Tracks