Disguised as a travel agent, Su Ji is a government spy with six years experience who can't reveal her career to her boyfriend Jae Joon. After she lies again, her boyfriend breaks up with her and leaves without notice, leaving her struggling alone with her sadness. Three years later, while chasing an industrial spy in disguise as a cleaning lady she happens to run into Jae Joon. He became an international certified accountant and seeing him throws her feelings into doubt. Jae Joon has become tired of his girlfriend's constant and suspicious lies. In one phone call, he tells her he is leaving korea to study in Russia. Three years later disguised as a distinguished international accountant, he enters the NIS(National Intelligence Service) as an agent in its overseas branch. He's a newbie who got a late start, but he's highly motivated a Russian crime organization, when he runs into Su Ji. It's shocking to see her now as a hotel cleaning lady but his affections for her...