The protagonist, previously known as Marie Setouchi, awakens to find herself reborn as Mariel Rosenstone, the five-year-old daughter of Duke Rudolf and Duchess Liselotta of the Kalkstein Kingdom. Mariel retains her past life's memories, including her previous life as Mariel Rosenstone, where she was a notorious "villainess" manipulated by the saint Eliana. Her first life ended tragically, but her wish to own various animals, including dragons, was granted in this reincarnation.
Mariel's mother, Liselotta, is a powerful court magician who, in Mariel's past life, died protecting the Crown Prince of the rival Krytarion Empire, leading to a peace treaty. This act earned her the title "Miracle of Kleina." Mariel, as Liselotta's daughter, was betrothed to Prince Edouard, but her lack of magical talent earned her the nickname "Clumsy Princess."
Upon waking, Mariel discovers she was reborn with her memories intact and her parents alive and loving, a stark contrast to her previous life. She also finds she is holding a dragon egg, which hatches into a small, adorable dragon named Luria. Liselotta permits Mariel to raise Luria, who is revealed to be an Ancient Elemental Dragon.
Mariel's primary goal is to prevent her mother's death during the upcoming Third Kleina War. She also wishes to avoid her arranged marriage to Prince Edouard and live a peaceful life. She begins practicing magic, discovering that her unique, reversed mana circulation, which made her "clumsy" in her previous life, is compatible with the Japanese language she remembers. This allows her to cast spells effectively when using Japanese incantations.
Her magic training is overseen by Rashid, an Ancient Elemental Dragon and Luria's father, who can transform into a human. Rashid's wife, Reyli, also an Ancient Elemental Dragon, frequently visits, often in the form of a Russian Blue cat, to check on Luria and Mariel. They reveal that the Crown Prince Bernhard of Krytarion is not human but a "demon" (a hybrid of demon and human bloodline), making his supposed attack by monsters in the past life highly improbable.
Rashid proposes a plan to prevent the war: Mariel will duel Crown Prince Bernhard. If she wins, her wish will be granted. The duel takes place at the site of Mariel's previous life's fall. During the fight, Bernhard, who can use magic without incantation and possesses immense power, reveals he can resurrect fallen combatants. Mariel, utilizing her unique mana circulation and Japanese incantations, creates powerful magic, including a defensive barrier and elemental summons. However, a clash between her water spirit and Bernhard's fire spirit causes a massive explosion, throwing Mariel into a tree.
Bernhard rescues Mariel from the tree, and despite her initial refusal, he proposes marriage, which she rejects, stating her desire for a peaceful life with her "fluffy companions." The duel is interrupted by the arrival of Rashid and Reyli, who have been observing. The narrative ends with Mariel having revealed her past lives and the true nature of the upcoming war to Rashid and Reyli, and with Bernhard's revelation of his demon heritage and his challenge to Mariel.
