After finding out her boyfriend has been cheating on her, Lee Daeun decides to forget him with a one-night stand. But as soon as Daeun returns to reality at her new job, she discovers that the guy she slept with is none other than Han Gyeoul, her boss! To make things even worse, he proposes to her out of the blue. Though shocked by his offer, Daeun gives him a chance. The only problem is, while Gyeoul may be a genius at work, he's a total fool when it comes to love! Does this pair have any hope?