This summary covers chapters 3 through 12 of the light novel, detailing the initial events and character introductions.
Chapter 3 begins with the dramatic summoning of a powerful, beautiful demoness with black horns and wings. She addresses the man who summoned her, stating her price for granting a wish is something precious. The man, stunned by her appearance, is unable to respond until the demoness attempts to read his mind. At that moment, he blurts out his wish: "Please marry me!"
Chapters 4-12 then shift focus to Theo Asper, an orphaned boy raised by a kind elderly couple who passed away when he was twelve. Left alone in a world where strength is paramount for survival against monsters, Theo joins the mercenary guild. Lacking combat skills, he works as a mere baggage carrier for various parties, receiving meager pay and often being blamed for failures. After a particularly hurtful expulsion from a party at fourteen, where he was mocked for his weakness and his deceased guardians, Theo seeks solace in the library. There, he discovers an ancient, tattered book containing a demon summoning ritual. Intrigued by the promise of a wish in exchange for a precious item, and hoping to gain strength, Theo performs the ritual in his home.
The summoning is successful, and the demoness, who introduces herself as Helvi, appears. Theo, captivated by her beauty, abandons his initial desire for strength and impulsively proposes marriage. Helvi, surprised and initially disbelieving, uses her ability to read minds to ascertain Theo's sincerity. She discovers his genuine admiration and affection, which is a novel experience for her, as most summoners are driven by greed. Despite her initial shock and internal turmoil, Helvi accepts Theo's proposal, forming a contract and becoming his wife.
The narrative then introduces Fiore Leotal, a kind receptionist at the mercenary guild who has a soft spot for Theo, viewing him as a younger brother. She worries about his mistreatment by other mercenaries, particularly a group led by a man named Carl, who exploit Theo for his labor. Fiore and the other receptionists are protective of Theo, finding his innocent nature endearing.
Theo, now married to Helvi, brings her to the guild, causing a stir due to her striking appearance. Helvi, to protect Theo from unwanted attention and to explain their sudden union, claims they are engaged, fabricating a story about their families being friends. This announcement shocks Fiore and the other receptionists. When Carl and his companions confront Theo, demanding he "lend" Helvi to them, Theo firmly refuses, declaring her his wife. Helvi, enraged by their disrespect towards Theo, incapacitates Carl by unnaturally twisting his arm. The three men flee in terror.
Helvi, now openly protective of Theo, accompanies him to accept the most difficult quest available: hunting a Chimera. Helvi reveals her immense power, stating she is "at least the strongest." They travel to the Chimera's lair, where Helvi effortlessly defeats the beast, demonstrating her overwhelming strength. She explains that in ancient times, she was responsible for the near extinction of powerful monsters, and the Chimera is now considered a lesser threat.
Upon returning to the city with the Chimera's body, Theo and Helvi are detained by the city guard, who are skeptical of their story. Helvi, annoyed by the delay and the disrespectful treatment, uses her powers to force the guards and their captain, Lauro, to kneel. Lauro, realizing Helvi's immense power, apologizes and explains they needed to verify the Chimera's identity. He expresses gratitude for their deed, as the Chimera had been a significant threat. Helvi, however, refuses any reward or medal, stating such things are a burden. She requests a reward from Theo in the form of his cooking, which he happily agrees to. The chapters conclude with Theo and Helvi leaving the detention area, their relationship solidifying as they head towards their home for Theo's promised meal.
