The story begins with the protagonist waking up with a severe headache and a bandaged head, realizing he's in an unfamiliar, spacious, and luxurious room, not his own apartment. He questions his whereabouts and how he got there, recalling only returning home from work, drinking whiskey, and going to bed. He discovers his voice is higher than he remembers, sounding like a child's. His confusion is met with shock and tears from a beautiful, bespectacled maid named Daphne and a dignified butler named Derrick, who address him as "Young Master Samuel" or "Sam."
It is revealed that the protagonist has been reincarnated into the body of Samuel, a nine-year-old boy, in another world. He retains his memories from his previous life as an adult salaryman. He learns that the original Samuel died after being severely beaten with a wooden sword by his half-brother, Manion, during what was supposed to be sword training. This incident triggered the protagonist's reincarnation.
Sam's new life is within the impoverished Baron Bach family, a minor noble house with a small territory. The family's culture heavily emphasizes swordsmanship, but Sam possesses no talent for it, making him an object of disdain for his father, Carius. His mother died when he was young, and his stepmother, Yolanda, who was formerly his father's mistress, dislikes him intensely. Yolanda actively campaigned to have Sam, as the eldest son, disqualified from inheriting the baronetcy due to his lack of swordsmanship, successfully paving the way for Manion. Sam's only solace comes from Daphne and Derrick, who cared for him after his mother's death.
Despite his bleak circumstances, Sam desires to experience an adventure in this fantasy world filled with monsters and magic. He rejects the idea of improving his family's fortunes, as he feels no attachment to them. Recognizing his complete lack of swordsmanship talent, Sam pins his hopes on magic, a rare ability in this world. He asks Daphne about magic books, and she tearfully agrees to procure some from his father's study, moved by his plight.
The next morning, Sam receives the magic books and, along with Daphne and Derrick, shares a meal separate from his father, highlighting his outcast status. He begins studying, discovering that magic requires internal magical power. He attempts a simple fire-starting spell, which, to his astonishment, erupts into a massive pillar of flame, scorching the ceiling. While initially panicked, he realizes this indicates he possesses significant magical power. He confides in Daphne, who, after some contemplation, agrees to keep his newfound ability a secret from his father, though she sternly warns him against reckless behavior. She also enlists Derrick's help in keeping the secret.
The following day, Sam ventures into the forest to practice. He successfully casts a body-enhancement spell, making him feel light and agile. He tests his newfound strength by leaping incredibly high and then by punching a large tree, effortlessly snapping it in half. He realizes this power could allow him to fight and potentially become an adventurer, a path that would let him escape his miserable home life. His confidence grows as he easily defeats a Wild Bear, a dangerous monster, with a single, devastating blow, splitting it in two. This victory solidifies his belief that he can achieve his goals and live freely.
One year later, Sam, now ten years old, is a respected figure in the town, despite his family's continued neglect. He single-handedly hunts Wild Bears, providing their meat to the townspeople and the orphanage, earning their admiration and affection. He has registered as an adventurer, though his young age prevents him from receiving a higher rank despite his exceptional combat prowess. The townspeople openly wish for him to become the next Baron, contrasting sharply with the disdain for his violent and spoiled half-brother, Manion, and the general dislike for the rest of the Baron Bach family. Sam's mother, Melanie, is remembered fondly as a kind woman who cared for the common people, a stark contrast to his stepmother, Yolanda. The story concludes with the townspeople lamenting that Sam, despite his kindness and strength, is not the heir, while Manion, who is cruel and undisciplined, is.
