Good Day (Korean: 굿데이) was a South Korean girl group formed by C9 Entertainment, with ten members: Heejin, Genie, Cherry, Chaesol, Nayoon, Jiwon, Haeun, Viva, Bomin and Lucky.
[2] In 2012, Haeun was part of a three-member girl group Littles, under Nega Network but never debuted and only released an OST for the drama The Great Seer.
In 2015, Heejin released her debut single titled "To Reach You", which features rapper Olltii.
[7] Jiwon was a model under teenage fashion online shopping portal Sonyunara.
[9][10][11][12] Ahead of their debut, the group's own reality show "Good Day 2 U" was aired from July 20 till August 10 through Naver V Live.
[14] 6 members of the group: Heejin, Genie, Chaesol, Jiwon, Viva and Lucky were confirmed to join the reality television series The Unit.
[28] On July 6, Genie, Cherry and Nayoon re-debuted again through the four-member girl group Irris.