Blue (A.S. BLUE)
- A.S. BLUE
"BLUE" is After School's sub-unit A.S. BLUE's debut single. The song "Wonder Boy" was used as lead track. The single was released on the same date as, the other After School sub-unit, A.S. RED's debut single, "RED". Both singles, promoted also at the same time, were released as the main group's 4th single.