Sienna is 18 years-old when her world is turned upside down. She feels broken and helpless and decides to enlist the secret services of Her Majesty Queen Elizabeth II. After a year of hard training, and a year of learning a foreign language, she is sent to Seoul to investigate the Fantagio Company and the Astro group. When she arrives in South Korea, she meets Moonbin, and, scared that this meeting will get in the way of her mission, she avoids him as much as possible. But, when she has to apply for a job for the company, she can't run away from him forever. Secrets, lies, romance and friendship, all get mixed up into a crazy adventure Sienna never dreamed of, even in her craziest fantasies.