The story begins with the protagonist, Fisel, on his deathbed, surrounded by his elven companions who express their sorrow at his impending demise. Fisel, a human, is aware of the vast lifespan difference between humans and elves. He has dedicated his final moments to developing a legendary spell, "Reincarnation Magic," a desperate attempt to overcome this disparity. Despite the low chance of success, he casts the spell on himself, hoping for a chance to reunite with his elven family. He expresses his desire for them to live freely but to welcome him back if he succeeds in reincarnating.
The narrative then flashes back twenty years, detailing Fisel's life in the magic-advanced Kingdom of Highhorn, bordering the Demon Lord's territory and the elven homeland. As a child, he lived in fear of monsters. Over time, human advancements in magic and weaponry led to the subjugation of monsters, turning them into a source of income and glory. When Fisel was twelve, the Demon Lord attacked the elven nation, leading to its swift collapse within a year, with rumors of the kingdom's complicity. The fall of the elven nation left its survivors vulnerable, stripped of their rights and often sold into slavery or hunted by monsters. Elves, known for their beauty and superior abilities, fetched exorbitant prices in the kingdom's black market.
Fisel, unaware of this grim reality, reached the age of twenty-five. His life took a turn when his meticulously crafted "Complete Recovery Potion" was recognized by the kingdom, granting him a patent and the promise of immense wealth. This achievement was the culmination of seven years of dedicated, self-taught research into potions, fueled by the tragic death of his father in a monster attack, a fate he believed could have been averted with proper healing items. Despite his humble beginnings and lack of formal education, Fisel's talent led him to a prestigious academy as a scholarship student. After three years of intense study, he returned home to focus on his research, eventually succeeding in creating the Complete Recovery Potion. He decided to sell a diluted version of his potion to the kingdom, ensuring a steady stream of income. However, he lamented that he couldn't achieve this success a year earlier, before his mother's death.
While celebrating his newfound fortune, Fisel is approached by Gelg, a reputable merchant who had just finalized the contract for his potions. Gelg invites Fisel to accompany him to the "underground," piquing Fisel's curiosity and apprehension. They venture into a secluded alley, leading Fisel to fear for his safety. Gelg reassures him and they arrive at a hidden door guarded by a hooded figure. Upon entering, Fisel is overwhelmed by the heat and noise, only to discover it is an "Elf Auction." He witnesses elves being sold for vast sums, a brutal reality that shatters his naive worldview.
During the auction, Fisel is deeply disturbed by the treatment of the elves. He witnesses a severely injured and sick elf, labeled as a "defective product" due to an unknown illness and past abuse, being put up for auction. Despite the low interest from other bidders, Fisel impulsively bids 10 million G, the highest bid of the day, and purchases the elf. He is then informed by the slave merchant about the rules of owning an elf, including the mandatory collar that prevents rebellion and ensures their return to the merchant if the owner dies, unless a family member claims them within a month. Fisel takes the injured elf, who is barely able to walk, and uses a "Teleportation Orb" to return to his inn. He administers his precious Complete Recovery Potion to the elf, who experiences a violent reaction before falling asleep. The next morning, the elf, now healed and named "Vel," expresses profound gratitude and pledges her loyalty to Fisel, mistaking him for a benevolent master. Fisel, realizing Vel's past trauma, decides to buy her new clothes and give her a name.
Fisel and Vel then visit a hairdresser and clothing store, where Vel's submissive demeanor and Fisel's lack of experience in such matters lead to humorous situations. They later visit a cafe, where Vel explains the harsh reality of elf treatment in their society: women are often bought for sexual gratification by nobles, while men are exploited for labor. Fisel, realizing his own social ignorance, reiterates his intention to help elves, not for personal gain but because he can. He decides to return home to prepare for his next steps.
Fisel contacts Gelg to inquire about upcoming elf auctions, seeking to hire more elves as guards. Gelg informs him of an auction that evening featuring spoils from a military expedition. Fisel attends the auction with Gelg's subordinate and witnesses the sale of a former elven knight commander. He then purchases a pair of twin elves, Ban and Aina, who were renowned knights but were blinded and rendered "defective" during the war. Fisel brings them, along with Vel, back to his secluded home.
Upon arriving home, Fisel retrieves his Complete Recovery Potions and prepares to heal Ban and Aina's eyes. Despite their initial distrust and fear, Fisel binds them and applies the potion, restoring their sight. He then reveals his plan: to develop a magic that can locate all elves and teach them how to create his recovery potion, enabling them to rebuild their nation. He explains that he bought them because he could save them, and that his ultimate goal is to change the world's perception of elves. He also reveals that he has hired a chef, Dunning, who had his tongue cut out, and that he intends to free all the elves he has purchased by removing their collars, while retaining the "master's command" magic for his own safety.
Fisel continues his work, aiming to develop the locating magic and improve his recovery potion. He travels to the capital with Aina on a dragon to procure more ingredients. He also attends another auction, where he impulsively buys a cursed elf named Shizuku, who is suffering from a mysterious ailment and has been betrayed by her companions. Fisel brings Shizuku home, along with Ban, Aina, and Dunning, and begins the arduous task of deciphering and curing her curse. He discovers that the curse is a powerful, life-threatening enchantment that will kill Shizuku within five days.
Fisel dedicates himself to breaking the curse, working tirelessly with the help of his companions. He manages to decode a portion of the curse and begins the process of reversing it. During this time, he learns more about his companions' pasts and their motivations. He also realizes the importance of having a skilled chef like Dunning, and the need for his elven companions to have a purpose beyond being his servants.
After a tense period of deciphering and treatment, Fisel successfully breaks Shizuku's curse, though he is unable to remove the physical marks of the enchantment. He also heals Dunning's tongue, allowing him to speak again. Fisel's actions lead to a complex dynamic within the household, with some elves questioning his motives and others expressing gratitude. The story concludes with Fisel and his growing group of elven companions living together, facing an uncertain future but united by Fisel's desire to protect and empower them.
