LOONA 1/3 (이달의 소녀 1/3; stylized as LOOΠΔ 1/3) is the first sub-unit of the girl group LOONA. They debuted with members HeeJin, HyunJin, HaSeul and ViVi on March 12, 2017 on Inkigayo with their song "Love & Live".
Later, LOONA member YeoJin was revealed to be the fifth member of the sub-unit, but was excluded from the first album, its repackage and following promotions.
LOONA 1/3 initially derived its name from it consisting 1/3 of LOONA's members.
A second meaning to the group's name occurs when their numbers are flipped to create "3 / 1". The "3" is said to represent HeeJin, HyunJin, and HaSeul (the first three members to be introduced), the "/" is YeoJin (YeoJin was revealed after HaSeul, making her a break between the reveal of members of LOONA 1/3), and the "1" represents ViVi (she was the sole member to be introduced after the break).
LOONA 1/3 is currently the sub-unit with the most MVs.
LOONA 1/3 reveal photo.
Juicebox teaser for group debut.
Debut group promo #1
Debut group promo #2
Innisfree & LOONA 1/3 pictorial for High Cut.
Backstage of Fantastic Duo with PSY (May 27, 2017).