After dying in a freak accident, a young man is reincarnated in a fantasy world by a goddess and receives the cheat skill Restoration, which can heal any injury or illness. Recognizing that his power has limited combat applications, the protagonist—now named Allen—devises a plan to buy cheap, defective slave girls from the market, heal them with Restoration, and live a leisurely harem life where the grateful slaves cater to his desires.

Allen purchases two slave girls, a beast-eared half-beast and a dark elf, and restores them to perfect health. To his dismay, the healing process awakens latent abilities in the girls that turn out to be extraordinary. They rapidly improve the estate’s crop yields, living conditions, and overall prosperity through their own cheats, solving every problem before Allen can step in. His attempts to use his modern-world knowledge only backfire, as the slaves absorb his ideas and execute them even better, making him increasingly irrelevant. The goddess occasionally appears to mock his predicament, and a running gag of misunderstandings ensues: the slaves interpret Allen’s awkward attempts at seduction as acts of selfless kindness, elevating him in their eyes as a saintly master, while he remains frustrated and unable to act on his true intentions.

As the story progresses, Allen accumulates more slaves—eventually fifty in number—and the misunderstandings escalate. The slaves’ gratitude and high expectations lead them to accomplish feats such as saving an ogre village from famine, eradicating racial discrimination in the region, and constructing a resort. Allen is later kidnapped, then appointed as a new demon lord by the lust demon king, a nine-tailed fox who takes a romantic interest in him. Despite his repeated failures and dwindling personal relevance, Allen’s reputation as a hero and leader grows wildly beyond his control, and the slaves’ continued success only deepens the comedy of errors at the core of the narrative.