An office romantic comedy that follows the story of a conglomerate heir and his new secretary, a former special forces officer now working undercover. Yun I Jun is a quirky third-generation chaebol raised in a sheltered environment who becomes a prime suspect in the mysterious murder of his previous secretary. When a new "male" secretary arrives to take the position, he has no idea that she's hiding a major secret. To uncover the truth, Kang Jae Hui, a former special forces officer turned police officer renowned as a "human weapon" for her exceptional strength and combat skills, disguises herself as a man and goes undercover as Yun I Jun's personal secretary and bodyguard. While protecting him, she secretly investigates him, setting the stage for unexpected chemistry, hidden identities, and plenty of comedic tension.