“You might find this hard to believe, but yes, I’ve fallen for you.” Executive Director of Taegang Group, the nation's top conglomerate, and the most likely successor to the throne. Starting as an intern, he proved his skills instantly with a lightning-fast promotion to Executive Director. With a suit fit that turns the office lobby into a runway and visuals that could easily pass for Taegang's official brand model, he is a perfect man who takes responsibility for both unrivaled performance and the visual welfare of his employees. However... If you look at this man up close... “He’s just a lunatic!” His erratic sensitivity drains the life out of his subordinates, and his perfectionist pickiness practically begs people to resign. After his secretary is found dead in a cabinet, he gains another title alongside 'Taegang Crown Prince.' 'Yoon I-jun, Prime Murder Suspect.' Since then, I-jun has remained in seclusion, and the sluggish police investigation has only spawned endless rumors. Then one day, I-jun suddenly announces he will hire an executive bodyguard to protect him... In Taegang Group, where the best of the best gather, a resume like no other appeared. The name is Kang Jae-hee. Aside from being from the special forces, the resume is full of blanks. I-jun found the disciplined posture refreshing and the unprecedented lack of sophistication amusing. That simple curiosity pulled Jae-hee across the threshold of employment. When the bodyguard saves him in a moment of crisis—which is just part of the job—his heart rate speeds up uncontrollably. Do I... like men? This isn't the time for this. ...What will be the choice of Yoon I-jun, the third-generation chaebol who has everything except love?

“Do not confess to me, sir. I am currently a man, am I not?!” A detective in the Seoul Metropolitan Police Agency's Mobile Criminal Investigation Unit and a former non-commissioned officer in the Army Special Warfare Command. A human weapon with a total of 9 dan ranks—5th dan in Judo, 1st dan in Hapkido, and 3rd dan in Taekwondo—and a completed military service record. She enlisted in the special forces at 19 but was discharged after witnessing a comrade's death. One day, while drifting without a sense of direction, she found her second calling by helping the police catch a mugger. While swinging handcuffs day and night to catch the bad, the weird, and the wicked... The problematic guy who stepped on her toes appeared. There was no way a third-generation chaebol who acted oblivious despite being a murder suspect would look good in Jae-hee's eyes. Thus, Jae-hee willingly disguises herself as a man to go undercover as I-jun's executive bodyguard. I-jun possesses all the traits a third-generation chaebol should have. A personality disorder, severe OCD, and a silver tongue for boasting. While chasing the truth while serving I-jun's every whim—a fate she never asked for—Jae-hee discovers that he, too, is receiving death threats. Once she takes off her biased glasses, he looks different. I-jun's OCD was a defense mechanism to protect himself, and his ruinous personality was a boundary drawn against people who only cared about his money. Detective Kang Jae-hee's goal begins to shift. To save I-jun's life from the gutter, to willingly accompany him in his lonely life, she decides to find the real culprit of the cabinet murder case and become his true hero. Because the only superhero who can save Yoon I-jun is Kang Jae-hee.

“My perfectly controlled life has been completely twisted. Ever since I met you.” Despite having the stunning looks and skills to be called the 'Face of Taegang,' she acts with extreme caution, believing a good secretary is the shadow of their boss. She is the very definition and standard of a secretary. But that's where it ends. The moment she leaves the office, she faithfully implements 'Enjoy My Life.' From 9 to 6, as soon as she clocks out, Hye-jung sheds her secretary persona and revives the self she had sealed away in her two-piece suit. Her posture, which was upright all day, transforms into a sexy wave under the club lights. The many nights she secretly burned away were the only outlet for Hye-jung to relieve stress. When the pitch-black night passes and dawn breaks, Hye-jung starts her daily routine again. For her, who lives well on her own, dating and marriage have no room to squeeze into her life choices. She believes all men are the same, and she has a history of getting badly burned by them. But one day, a guy who wasn't like the others appeared. Kim Si-hyeon, a man as fresh as seasonal greens. She tried to keep her personal and professional lives separate and drew a line to protect her long-held philosophy, but seeing Si-hyeon lose his mind for her, Hye-jung had an intuition. Kim Si-hyeon is the devil who came to destroy her life and her savior at the same time. Hye-jung has many worries. Can I trust this man? Can I show him my secret? Can I continue this 'secret romance with the enemy' that she can't tell is competitiveness, affection, or a fling? Although she is a key figure who knows more about Taegang's secrets than anyone else, Hye-jung dreams of being a kingmaker rather than the protagonist. Whether the secret left by Han Eun-young will be her end or her beginning, everything depends on Hye-jung's choice.