Kim Mi-So was exemplary secretary for Lee Young-Joon for 9 years. She put up with everything so she car earn enough money to pay out her family's debt. But now, she wants some time for herself and does not plan to give her life for work, but wants to find a romance with a regular guy. And so, she tells everything that she's quitting work. Lee Young-Joon finds that unacceptable, but hires Kim Ji-Ah as her replacement. During that one month period while Kim Mi-So is training her replacement, Young-Joon decided to put some work into making her stay, even if taht means he has to get involved romantically.