Five member South Korean girl group, formed by NAP Entertainment in 2011. They made their official debut with the song No No No No No on October 12, 2011. The group consists of Chemi (Leader), Re Dee, Effie, Ann J and Lenny. Their group name was taken from the first letter of each member's name. They are dubbed as the "5-IU Idols", being produced by the same producer as IU which is Choi Kap Won.