In July 2011 After School (애프터스쿨) was divided into two sub-groups, After School Red (애프터스쿨 레드) and After School Blue (애프터스쿨 블루). Both groups released a single and promoted their own songs at the same time. While A.S. BLUE features an innocent concept, A.S. RED features a sexy and powerful concept. Both groups' debut singles were released as After School 4th single.
|1||밤 하늘에||1,592 listeners|
|3||Night Into The Sky||29 listeners|
|4||In The Night Sky||11 listeners|
|5||밤 하늘에 (In the Night Sky)||7 listeners|
|6||밤 하늘에(In The Night Sky)||7 listeners|
|8||In The Night Sky (밤하늘에)||3 listeners|
|9||밤하늘에 (In The Night Sky)||3 listeners|