The story begins with Yu Sato, a 12-year-old boy, experiencing his own death at the hands of his abusive stepfather. Filled with a burning desire to become a "taker" rather than a "taken," Yu awakens in a new world. He finds himself in a simple room, cared for by a kind elderly woman named Stella. Yu quickly realizes this is not Earth; he is on the continent of Lem, in the village of Ressle. His black hair and eyes are unique here, as everyone else has different colored hair and eyes. He discovers he can see people's stats like in an RPG, and his own status reveals a unique skill: "Otherworldy Magic Eye LV1." Determined to survive and thrive in this new world, Yu vows to become a "taker."
A month later, Yu has learned the basics of this world from Stella, including its currency and customs. He learns about monsters and the Guild system, where adventurers register. Ressle Village only has an Adventurer's Guild that handles all functions. While trying to report a herb-gathering quest, Yu encounters Hage, a local adventurer who bullies him, physically assaulting him. Yu's stats are no match for Hage's, and he's further angered when the Guild Master treats him with contempt and shortchanges him on his reward. Yu also discovers his Guild Card is a fake, leaving him without proper identification. He resolves to earn money, gain levels, and learn to fight, realizing that without weapons or the ability to buy them, this will be a challenge.
Yu continues his daily herb-gathering quests, facing the Guild Master's continued poor treatment. He learns about goblins, a common and troublesome monster. During a gathering trip, he witnesses Hage effortlessly defeating three goblins. Yu observes Hage using some kind of energy to enhance his physical abilities, which depletes Hage's MP. This sparks Yu's interest in replicating this ability. After a week of dedicated practice, Yu finally manages to manifest a similar energy, which he identifies as "Fighting Spirit" and can use to enhance his physical capabilities. However, his low MP limits its duration.
Yu's "Otherworldy Magic Eye" evolves, allowing him to see more detailed information about stats and skills. He learns that "MP" is used for magic and fighting techniques and can also be used for physical enhancement. He also discovers that his "Otherworldy Magic Eye" has leveled up to LV2, granting him more detailed insights. He continues to train his "Fighting Spirit," which he learns is an active skill. He also begins practicing "Sword Skill" and "Magic," aiming to improve his combat abilities.
Yu's life takes a drastic turn when Hage and his companions ambush him at the Guild. They reveal that the entire village, including the Guild Master, has collectively decided Yu and Stella are unwelcome and have ordered Hage to drive them out. Yu, enraged by this betrayal and the threat to Stella, unleashes his "Steal" skill on Hage, taking his "Swordsmanship LV1," "Strength Up LV1," and "Fighting Spirit LV1." This act causes Hage's skills to disappear, and Yu gains them, leveling up his own "Swordsmanship" and "Fighting Spirit." Yu then confronts and kills Hage, embracing his new role as a "taker."
After killing Hage, Yu begins to practice his "Steal" skill on captive Orcs, successfully acquiring "Strength Up LV1" and "Fighting Spirit LV1." He then confronts the Guild Master, Cast, who had been skimming Yu's quest rewards. Yu uses Hage's stolen sword and his enhanced abilities to intimidate Cast into returning the stolen money and surrendering his "Blacksmithing LV1" and "Alchemy LV1" skills. Yu leaves Ressle Village, having taken what he felt was owed to him.
On his way home, Yu encounters Nina Reba, a Level 12 Thief. Nina, who had been observing Yu, offers to become his friend and partner, citing his inability to accept quests and her skills as a Thief. Yu, still distrustful, initially refuses but eventually agrees to a partnership, warning her against any misbehavior. Nina's skills prove invaluable, allowing them to take on more dangerous quests in mountain caves, where Yu acquires new skills like "Search LV2" and "Strength Up LV3" from various monsters.
Their partnership faces a challenge when Nina is ambushed by Nuts and Coco, Hage's former companions, who suspect Yu of Hage's disappearance. They attempt to assault Nina, but Yu intervenes, killing them with his enhanced skills. He then comforts Nina, acknowledging their friendship. Yu continues to develop his skills, building a bathhouse and aiming to master blacksmithing and alchemy, while Nina persistently tries to become his friend. The story concludes with Yu and Nina working together, with Yu's skills and Nina's support, as they venture into more dangerous territories.