The narrative follows a recurring cycle where the Hero, empowered by a god to defeat the Demon Lord, ultimately dies at the hands of humans after achieving victory. The story is primarily told from the perspective of a powerful magic-user, who is revealed to be part of the Hero's party. Her motivation stems from a deep, unrequited love for the Hero and a profound sense of injustice at his fate.
Initially, the party successfully defeats the Demon Lord after three years of arduous travel, securing a century of peace. However, the Hero's impending marriage to the Princess, a pre-arranged political alliance, becomes the catalyst for his demise. He is poisoned shortly after his triumphant return. The magic-user, devastated and unable to resurrect him through conventional means, discovers a difficult and costly time-rewinding spell. Her initial attempts to save the Hero are driven by a naive belief that his strength and status would suffice if he were simply alive.
Upon rewinding time, she witnesses the Hero's death by poisoning again, realizing it was not an accident. Her investigation reveals that the country's nobility harbors resentment towards the Hero's marriage to the Princess. Driven by her desire to fulfill the Hero's dream of a happy life with the Princess and bring peace to the kingdom, she repeatedly rewinds time, paying increasingly heavy prices for the magic, including memories and a cherished grimoire. Despite her efforts to prevent the poisoning, the Hero continues to die, often in different circumstances, leading to the erosion of her own memories and physical appearance, forcing her to conceal her face.
A turning point occurs when, after an unknown number of loops, the Hero unexpectedly declares the annulment of his engagement to the Princess during a celebratory banquet. This deviation from the established tragic outcome offers the magic-user a glimmer of hope, suggesting a hidden element at play. The Hero states his desire to travel the lands to hunt down remaining demon remnants, a claim that puzzles the magic-user as no such powerful demons are known to exist. The King grants him permission and funds, while the rest of the party receives their usual rewards. The Princess appears less distressed than expected, hinting at her own motivations.
The narrative then shifts to the Hero's perspective, detailing his divine mandate to defeat the Demon Lord and the blessings he received: "Inheritance" and "Grace of the Goddess." He learns that "Inheritance" allows him to pass on his abilities to the next Hero, but not his memories. He is also granted a blessing that mitigates mental attacks.
Back to the magic-user's perspective, she realizes the Hero's repeated deaths after defeating the Demon Lord are due to humanity's fear of his overwhelming power, particularly from the nobility and royalty who orchestrated his assassinations through political machinations. This time, the Hero has seemingly severed ties with these factions, but the magic-user fears he is still in danger. She decides to protect him directly, casting a protective spell and subtly warning him.
The Hero, seemingly aware of her intentions, reveals he has abandoned the pursuit of ordinary happiness. He touches her hair, lamenting the loss of its original color, a consequence of her magic. He then proposes they travel together, not to fight demons, but to explore the world and "heal the curse" that has befallen her. He asserts that she, too, is a hero and deserves happiness, as she was instrumental in defeating the Demon Lord. This declaration leaves the magic-user bewildered, questioning the Hero's definition of happiness and his apparent foreknowledge of his own fate.
The story then briefly adopts the Princess's viewpoint. She recounts her initial dismay at being betrothed to a commoner, a decision she protested but was dismissed by her father, the King. She believed this arrangement would be temporary, but the Hero's victory solidified the marriage pact. Desperate, she obtains a "witch's secret medicine" from a back-alley shop, intending to poison the Hero during the wedding banquet. She succeeds, believing this will lead to her own happiness.
Finally, the narrative returns to the Hero's perspective, revealing his past trauma of his hometown being destroyed by demons. He receives numerous blessings from a goddess, one of which is "Message." He discovers a book containing messages from himself to himself, detailing his repeated deaths and the circumstances surrounding them, including being poisoned by a doctor and later dying of starvation while confined. He realizes he is trapped in a cycle of reincarnation and murder, suspecting a conspiracy. The book reveals his attempts to warn himself and his growing fear of the endless loop and the unknown perpetrators.
