Girl group trainee Yura gets pushed off a chair the night before she makes it to the finals, transmigrating into the body of the villainous princess of a mysterious kingdom called "Adalante," who happens to share her name. From what she read in the book "The Mystery of the Fall of Adalante" before crossing over, Yura realizes that all the theories regarding the fall of Adalante have something to do with the wrongdoings of the princess. In fact, the fall of the kingdom coincides with the princess's death. Will Yura die, or will she change history? The countdown to destruction begins. Let's see how one girl changes the fate of Adalante~