EXO-K and EXO-M have been friends forever. They went through orphanage and difficulties together but having to grow up in the streets made them realize something ; that they needed to protect themselves. They learned to fight and as they grew up, became the most lethal gang in town. A Secret Security Organization hired them as infiltrated protectors. Through their life, they've been through a lot and all have their own fear of something... And a common secret. What will happen when they'll have to protect worlwide K-Pop girl group Girls' Generation ? Will that be a mission like another or one they'll never be able to forget ?