The story picks up with the hero party, including the protagonist Roland, a mage named Lina, a priest named Seraphin, and a holy knight named Elvi, preparing to confront the Demon Lord. Roland, possessing the "Shadowy Presence" skill, is tasked with assassinating the Demon Lord while the rest of the party distracts him. Despite Roland's suitability as a decoy, the hero, Almeria, insists on this plan for the highest success rate, acknowledging Roland's unique capabilities. The party is exhausted from their journey, and a somber mood hangs over them, with the unspoken fear of casualties. Roland, however, slips away under the guise of using the restroom, intending to carry out his true mission alone.
Roland infiltrates the Demon Lord's castle through a secret route, bypassing the main entrance. He skillfully breaches the Demon Lord's audience chamber, a feat the party believed impossible. Inside, he confronts the Demon Lord, a beautiful, red-haired, red-eyed female demon. Roland's "Shadowy Presence" skill proves highly effective, confusing the Demon Lord by making him appear and disappear. The Demon Lord's immense power is evident as her magic easily destroys parts of the chamber, but her inability to track Roland's movements due to his skill leaves her frustrated. Roland exploits the Demon Lord's lack of recent combat experience, a critical weakness against his honed assassination skills. He swiftly defeats her with a simple dagger, fulfilling his mission.
After the Demon Lord's defeat, Roland reports to King Randolph, who is impressed by his swift victory. Roland downplays his role, emphasizing the party's contributions and the king's initial request to credit Almeria and her party with the Demon Lord's demise. The king reveals that Almeria and her companions have spoken highly of Roland's impact on the party's effectiveness. Roland, however, desires anonymity and rejects offers of reward, including marriage to Princess Almeria. Instead, he expresses a desire for a "normal life," a concept he struggles to define but envisions as a life free from killing, betrayal, and constant danger, filled with simple comforts.
The king agrees to help Roland achieve this goal, providing him with funds. As Roland leaves, a black cat, later revealed to be the former Demon Lord Lyra, follows him. Lyra, stripped of her power by a magical collar Roland possesses, becomes Roland's companion. They travel to the town of Lahati, where Roland seeks employment as a guild staff member, believing it to be a step towards a normal life. He impresses the guild branch manager, Iris Nagan, with his unique skills during a "normal interview," which involves him demonstrating his abilities by subtly manipulating her clothing.
Roland begins his new life as a guild staff member, working alongside a junior named Miria and a senior named Molly. He navigates the mundane tasks of the guild, including handling quests and dealing with adventurers. He demonstrates exceptional observational skills and combat prowess when intervening in a dispute involving Molly and an adventurer with a forged adventurer's license, effortlessly subduing the troublemakers. His actions, though seemingly simple, reveal a hidden depth and skill that surprises his colleagues.
Roland continues to adapt to his "normal" life, seeking a suitable home with Lyra and Miria's help. They find a secluded house outside of town, which Roland cleans and prepares. During this process, they discover a Dark Plasma monster, which Roland swiftly defeats, revealing his combat capabilities to Lyra and further solidifying his unusual nature. He also learns about the concept of "normal family life" from Miria's parents, a profound experience that solidifies his understanding of his goal.
Roland's work at the guild continues, where he assists adventurers with quests. He demonstrates his keen eye for detail by identifying a potentially dangerous quest for a D-rank adventurer and later by discovering a missing adventurer in a cave inhabited by a formidable Gray Bear, which he incapacitates without killing. His actions, though often understated, consistently protect others and prevent harm, earning him respect and admiration, even as he maintains his desire for a quiet, ordinary existence. He continues to be accompanied by Lyra, who observes his actions with a mixture of amusement and grudging respect.