Suddenly thrust into a novel she used to read, the newly transmigrated Duchess Erina Valois finds herself with a lot on her plate. In her previous life, she was a simple call center employee, and now, she must take on the role of an adviser to the tyrannical emperor of the Heathronia Empire, Cardan Zeon. To Erina, Cardan is all too similar to the infuriated customers she's used to. Their grievances pale in comparison to Cardan's wrath, however, as he is notorious for beheading his subjects over just about anything.

To complicate things further, the novel seemingly left out the details of her and Cardan's relationship; Erina quickly realizes that she is no mere adviser. She and Cardan are supposedly bound by a contract, with Cardan compelled to do her bidding in exchange for something she owns. Knowing that one wrong step could result in her execution, Erina must tread carefully around Cardan and use her experience dealing with complaining customers to ensure his satisfaction, all while attempting to find what exactly in her possession Cardan so desperately wants.