Lila, an ordinary girl, sneaks into Moonfall Castle to save her mother and becomes the study companion of the brutal young master Elias. Brave and tough, she tames the unruly young master with her courage, strength and wisdom, and they gradually fall for each other. Later, they enter the palace to guard the princess, fight against powerful nobles and make remarkable achievements repeatedly. In the end, Lila and Elias jointly quell the conspiracy, both receive noble titles, and embrace a happy ending.