7th Grade Civil Servant

Two wannabe spys break up when one of them gets fired. Years later, both end up being spies working for different units, so they have to keep their covers up in real life. Gil Ro use his real identity, hence why he was simingly fired, to spy on his rich father. So, when Kim Seo Won appears as a new employee, he wonders if she really is just a doppleganger of the woman he loved.