Do hyun is the heir of a multi million company but he has a secret to protect. Do hyun has a condition called D.I.D. or dissociative identity disorder or muliple personality. To help him prepare for his role in their company and control his different personality he employed the help of a psychiatrist, Oh Ri Jin.
Se ki is one of the personality of Do Hyun, among his personality Se ki is the most vicious and darker personality.