"He has nothing appealing about him. He’s all shell, nothing inside." At a hotel she visits for a friends’ gathering, Han Dajeong runs into her ex-boyfriend—the same one who cheated on her. Shameless and clingy, he keeps pestering her, and to shake him off, she ends up pretending to be the girlfriend of a man she bumps into by chance: Baek Junho. At Junho’s suggestion, the two share some drinks… and in a moment of impulse, Dajeong spends the night with him. "I think it’d be nice to have someone to drink with." "It won’t be fun. I’m a stiff person." "Ms. Han Dajeong. At the very least, you’ll be fun for me." It was the first night where Dajeong truly felt her senses awaken, but she tries to think of it as nothing more than a one-night fling. However, for some strange reason, Junho’s insomnia disappears when he’s around Dajeong, and after sleeping soundly for the first time in ages, he wants to see her again. "Give me your number. There’s something I want to check." "Listen carefully. You were just a one-night thing to me." Believing the relationship is over, Dajeong pushes Junho away with harsh words… But then she meets him again. "I’m Baek Junho, the new chairman of Baekun High School. I look forward to working with you, Ms. Han Dajeong." Junho returns to her life… as the new chairman of the high school where Dajeong works as the school nurse.