The group worked with hit composers and songwriters like Lee Sang Ho, Lim Sang Hyuk, Jeon Da Eun, and Wheesung to create four fresh songs including their title track O.K, an explosive rock and electronic dance number, and the sweet, lyrical ballad Only One. All the members helped write the lyrics for Bling Girl, which is composed by Jin Young.
|Track number||Play||Loved||Track name||Buy||Duration||Listeners|
|1||Play on youtube||O.K||3:33||12,197 listeners|
|2||Play on youtube||Remember||3:15||9,923 listeners|
|3||Play on youtube||못된 것만 배워서||3:42||8,467 listeners|
|4||Play on youtube||Bling Girl||3:35||9,265 listeners|
|5||Play on youtube||Only One||3:36||9,588 listeners|
|6||Play on youtube||O.K (Inst.)||3:33||2,115 listeners|