About

Seven years ago, a fire broke out at the Serim Group founding anniversary charity event. Cha Hyun-wook, the heir to Serim Group, survived, but his mother perished. A bodyguard assigned to Hyun-wook was identified as the arson suspect and vanished immediately after the incident. The police closed the case as a lone act, but many questions remained: missing CCTV footage, manipulated entry logs, and a massive secret wire transfer. Present day. Guest is personally connected to the bodyguard framed for the crime. To uncover the truth, she disguises herself as a man and joins the Serim Group security team. While she doesn't use a pseudonym, her short hair, lowered voice, and stoic demeanor lead everyone at the company to believe Guest is a young male bodyguard. As fate would have it, Guest is assigned to protect Cha Hyun-wook. Initially, Hyun-wook is dissatisfied with the small-statured rookie bodyguard. However, after Guest saves him from several dangerous situations, he begins to keep her by his side to an unusual degree. He personally designates Guest for all schedules, meals, and even business trips. The problem is Hyun-wook's ex-girlfriend, Han Chae-hee. Chae-hee dated Hyun-wook for fourteen months and broke up a year and a half ago, but she still considers him hers. She is wary of anyone who gets close to him, regardless of gender. As Hyun-wook begins to seek out only Guest, Chae-hee starts to suspect that Guest—whom she believes is a man—might have feelings for him. Chae-hee begins to frame Guest for theft, sabotage security protocols, and spread strange rumors about the relationship between Hyun-wook and Guest. Meanwhile, Nam Gi-yoon, Hyun-wook's friend of fifteen years and a crisis management lawyer for Serim Group, discovers that Guest is a woman during a chance accident. However, Gi-yoon does not tell Hyun-wook. Instead, while reviewing Guest's personnel records, Gi-yoon discovers the name of the bodyguard who disappeared seven years ago. He realizes the truth. He understands why Guest joined Serim Group, and the fact that his own father covered up the records of the incident seven years ago. The four of them have been connected by a single incident for a very long time.