When Yeo-Eun gets a text message from her boyfriend with details about a hotel room and a time, she is overjoyed. But it’s too early to celebrate because a few minutes later, he sends her another message saying that the first one was for his team’s after-party event. Although slightly disappointed, she decides she should surprise him at the hotel nonetheless. Unfortunately, when she gets there, she witnesses her boyfriend with another woman walking right toward her. In a moment of panic, Yeo-Eun grabs the man in front of her and steals his lips to keep herself from being caught. As it turns out, she just kissed the fiancé of the woman her boyfriend was having an affair with! Now suddenly, Yeo-Eun finds herself caught up in a whirlwind of events full of romance and revenge.