Lisa Fortan is the second princess of an empire whose supernatural power/ability is considered a proof of nobility. She grew up being looked down upon as an "incompetent princess" because she didn't have any supernatural powers, and although she was troubled by the label and the handicap of being the only one in her family to have any supernatural powers, she was forced to do the official duties that were forced upon her by her siblings who did whatever they wanted. She was doing her best. One day, Lisa's mansion is suddenly engulfed in flames. Due to her work performance, her brothers and sisters were jealous of Lisa's rise to fame despite her incompetence, and plotted to assassinate her. However, before she knew it, she had relapsed a year before her assassination. Returning to her past, Lisa decides to take revenge on her brother and sister who discarded her, and asks her estranged childhood friend, the knight Theodore Leuven, to help her. The incompetent princess, who was exploited until her death, begins to exact revenge on the supernatural beings who have fallen under her power.