So, SS501 junior Rainbow song titled Not Your Girl is actually a reply to SS501 hits U R Man!
It is no surprise since both songs are written by the same person. U R Man from SS501 is about a man who missed the girl who left him and the guy can’t seem to forget the girl he loved, whilst Rainbow’s Not Your Girl is about a girl who left the guy. Rainbow will start promoting the song in this week’s KBS Music Bank. Listen to the song here [link]