Everyone has a dark side within us. What will happen when the one you are sent to protect secretly has a darker secret than yours. The facade that everyone sees isn't who he really is. What if you two were born to be enemies? What if love blossoms between two impossible people? What if the mission fails? What if you are forced to sacrifice the person you loved the most for a greater good?

Name: Lee Hyunmi

Age: 18

Chararcter: Kind, sweet and smart

Alias: Sapphire

Alias character: Dealthly, strong and heartless

Name: Kim Joonmyun

Age: 21

Character: Heartwarming, sweet, gentle and lovable

Alias: Suho

Character: Heartless and cold