Princess Leticiel, heir to a small kingdom and its most powerful sorcerer, seemed to have everything, including a devoted partner named Nao, a mysterious young man who fell from the sky into her world. After a neighboring kingdom invaded, Nao was killed in battle. Rather than surrender, Leticiel took her own life, expecting the end. Instead, she awoke a thousand years later in an unfamiliar body. She now lives as Drossell, the unloved and seemingly talentless daughter of a duke, despised by her family and her own fiancé, the crown prince.

As she struggles to understand her new life in a world that has forgotten her former kingdom, Leticiel makes a shocking discovery. The art of sorcery, the powerful aether-based magic she once mastered, has been almost entirely lost. In its place is a far weaker, less refined form of magic that she finds utterly pathetic. Her primary frustration, and a driving force for her actions, is that the magecraft of this future era is incredibly lame. Determined to prevent the tragedies of her past from repeating and to uncover the truth of her reincarnation, she sets out to use her vast knowledge of true sorcery, even while trapped in a body with no innate magical ability.

She quickly learns that the world has not stood still. A dangerous black fog or miasma threatens the land, and Drossell is caught in the middle of competing prophecies, with some hailing her as a demon and others as a savior. She is also troubled by the fate of the original Drossell and is determined to do right by the girl whose life she has inherited. Her situation grows more complicated when she encounters Zeke, a young man who stirs memories of her lost love, Nao. However, Zeke has no memory of their past life, forcing her to decide if and how to reconnect with him.

The narrative follows Leticiel as she is summoned to the castle by the king, who seems to believe in the prophecy of her as a savior, and agrees to a deal in exchange for her freedom. She later returns to Lucrezia Academy, where she starts a Magic Club to teach others. After she and her friends survive an attack by twin spirits believed to be extinct, she is forced to reveal her true power. The story expands from the school grounds to a camping trip that turns into a nightmare when bandits capture her friends. This leads her to a masked figure connected to the dangerous black fog, who seems to know her former self, Drossell, hinting at a larger conspiracy tied to the conqueror from her original life. As she and Zeke work to purify cursed stones and fight the miasma, they uncover that their fates, the masked man, and the legendary elementals are all inextricably linked.