Sunny Hill was quickly thrown into their first project under Nega Network by featuring on Narsha's digital single "Mamma Mia". Janghyun did not vocally participate in the track, but was featured in the music video. The group quickly became known as "Narsha's Group", due to lack of popularity amongst fans of K-pop. Following promotions of "Mamma Mia", Nega Network introduced a new member for the group, Misung. The quintet released single "Pit-A-Pat" for the Korean drama "The Greatest Love". The song attracted much attention and charted high.