Masumi Todo is a violinist who gave up on her professional career after failing an international competition. Despite her disappointment, she was unable to give up her violin, but one day she suddenly fell down the stairs and found herself lost in another world. In the midst of the chaos, she was accused of being a spy and taken to a facility where she was forced to explain herself to the commander of the Knights, Ark. In this desperate situation, it was the "violin" that had come with her to the other world that brought a ray of hope to Masumi's destiny.