The story begins with a Japanese salaryman, recently deceased after saving a girl from a truck, being informed by a divine administrator that his death was an error. Rejecting the moral implications of taking over a living person's body, he is reincarnated into the body of Eleanor di Montpelier, a 7-year-old noble girl in a magical fantasy world. He retains his adult memories and finds himself bloodied and disoriented in a forest, having just survived a bandit attack that claimed her retainer.
A blunt, tsundere pixie named Dona appears as a temporary guide, revealing Eleanor's tragic past as an unwanted child of Count Montpelier, constantly targeted and despised by her family. Dona also informs the protagonist (now Eleanor) that the god granted him temporary immortality (lasting about six months) and the ability to use fire magic, which she quickly masters by imagination.
The immediate conflict arises when the bandits pursue Eleanor. Initially hesitant to take a life, Eleanor is brutally cut down by a bandit. Her temporary immortality activates, instantly regenerating her. This traumatic experience, coupled with the realization that she must kill to survive, hardens her resolve. She retaliates with Fireball, burning the bandit to death. Dona then reveals a forbidden magic called "Ability Drain," which allows her to steal abilities and magic from others. Dona maliciously tricks Eleanor into performing the drain in a humiliating manner, forcing her to straddle the burnt corpse and absorb magic through a bodily orifice. Despite the psychological and physical discomfort, Eleanor endures it, driven by her desperate need for strength. She gains increased magic capacity and the ability to control a sword with magic, naming the bandit's sword "Eleanor Buster" as a symbol of her newfound resolve.
Eleanor then journeys to the nearby city of Frontignan, exhausted and wary. She is taken in by a kind farmer's family before being brought to a guard station, where she is treated with suspicion. Dona reveals more about Eleanor's corrupt noble family, including her philandering father and a half-brother, Emile, who lives in Frontignan. Eleanor is eventually taken in by Brigidda Scarhouse, a shrewd merchant and former Montpelier family member who had cared for Eleanor as a baby. Brigidda, believing Eleanor has amnesia, offers her shelter.
However, the city proves to be as dangerous as the wilderness. Police Knights visit Eleanor, revealing the bandit she killed was one of their own, Gauthier, and implying Eleanor is involved in a larger conspiracy. They attempt to intimidate her and offer "protection" that feels more like surveillance. Eleanor realizes the city's authorities are complicit in the attempts on her life. That night, she is poisoned, but her immortality saves her again. Dona reveals that the original Eleanor possessed knowledge of poisons due to her past and mockingly suggests eating clover to access these dormant memories.
Seeking this crucial knowledge, Eleanor ventures outside the city gates. She encounters a genuinely kind old farmer who offers her delicious, fresh tomatoes, a stark contrast to the hostility she's faced. This act of selfless kindness deeply moves Eleanor, highlighting the emotional toll of her new, dangerous life. The farmer helps her gather clover, explaining its flower language ("Remember me") but doubting its magical effect on memory, leaving Eleanor to ponder how to truly unlock Eleanor's past knowledge. The chapter arc shows Eleanor's transformation from a confused victim to a determined survivor, forced to embrace brutal realities and navigate a world where even apparent allies can be enemies, all while seeking the means to protect herself.
