One night, LS Corp intern Han Ji Eun gets drunk and has a one-night stand with the company's CEO, Bae Seo Jun. She flees in panic but accidentally leaves behind her friend O Yun Ju's resume. Seizing the opportunity, Yun Ju takes her place to stay by Seo Jun's side, while Ji Eun becomes his secretary due to her plain appearance. As Seo Jun grows suspicious, Yun Ju schemes against Ji Eun to keep the secret hidden