A young woman named Cesia, who works as a servant for a viscount, finds herself attending the prestigious Royal Academy as a substitute for the viscount's lazy and pampered daughter. The promise of a substantial monetary reward upon her successful graduation drives her to accept this risky deception, as it would allow her to live the rest of her life without worry. She endures the weak bullying of the noble ladies at the academy while being worked to the bone at the mansion. However, just before she is set to graduate, she is tricked, and her entire payment vanishes. Furious and determined to get even, her plans take an unexpected turn when the second prince of the kingdom appears and offers her his help.

The central character is Cesia, a spunky heroine whose motto is determined resistance. Her counterpart is the mischievous second prince, Marcus, a man who is willing to put his life on the line for his country. Their meeting sparks a love story set against the backdrop of royal politics and intrigue. The setting is a fantasy kingdom with a rigid class system, where the Royal Academy serves as a primary stage for the first part of the story, after which the scope expands to include the royal court and matters of state.

The narrative begins with Cesia's time at the Royal Academy, but the plot quickly evolves beyond the initial premise of a simple academic deception. After her pay is stolen and she is recruited by Prince Marcus, her role shifts dramatically. Her mission for revenge soon turns into a larger assignment as she is drawn into working as a spy for the prince. The story covers a significant amount of time, with early chapters spanning years and the school setting becoming a smaller part of the overall narrative. By the end of the first volume, Cesia has joined a spy organization, and the book concludes on a dramatic cliffhanger where she is discovered by enemies and forced to leap from a balcony to escape.

The second and final volume follows Cesia as she is ordered to go undercover to investigate Juliette, a suspicious princess from a neighboring country who is also Marcus's fiancée. Disguised as Juliette's maid, Cesia must endure unreasonable requests while hiding her love for Marcus. Her mission goes catastrophically wrong when she falls for Juliette's trap and is almost driven out of the kingdom. With no one believing her side of the story, Cesia is forced to go into hiding as a fugitive from the law. It is at this low point that Marcus appears, and she must find a way to clear her name and stand beside him as an equal.