From 2012 to 2014, member Somin was a member of DSP Media's Japanese girl group Puretty with releasing singles "Cheki☆Love" in 2012, "Shuwa Shuwa BABY" in 2013 and then disbanded in 2014 with plans for the members to re-debut into other groups [REF].
On December 13, 2016, they released their first project single titled "Oh NaNa" featuring labelmate Heo Young-ji as a hidden member.