The story begins with Haruki Tachibana, a high school student, lamenting the end of summer vacation and realizing his refrigerator is empty. He heads out to a family restaurant but forgets his smartphone. Taking a shortcut through an alley, he gets lost. Upon finding the family restaurant, he rushes to cross the street, only to see a truck speeding towards a child. Haruki instinctively pushes the child to safety, sacrificing himself to the truck.
He awakens in an unfamiliar place, realizing he has been reborn as a baby named Ox Fon Terran. Five years pass, and Ox, now five years old, is aware of his reincarnation and the existence of magic in this new world. He has been training in swordsmanship under his dedicated maid and sword instructor, Aisha, who is exceptionally strong due to the dangerous nature of their home, the Dias territory in the southern part of the Saimar Kingdom. His father, Rein Fon Terran Dias, is a border count, and the region is prone to attacks from neighboring countries and monster incursions from nearby dungeons. His mother, Fal Fon Terran, is also a formidable magic user. Today is Ox's "Baptism," the day he will pray to a god to receive his elemental attribute and skills, and finally learn magic.
After the Baptism ceremony, Ox is transported to a void where he meets Iria, a goddess. She explains that his reincarnation was an accident, a consequence of his soul being pulled to this world during a hero summoning ritual at the exact moment of his death. This world is facing an unprecedented crisis, and Ox, as an anomaly, was initially meant to have his memories erased. However, his dying wish to become someone who could save others led to his survival and reincarnation. Iria grants him the power to protect people, and he receives a pocket watch.
Upon returning to the temple, Ox checks his status screen. He discovers a skill called "Creation," which allows him to create skills, and it is ranked "Mythical." He quickly hides his status before his parents can see it. When asked about his skills, he fabricates "Spirit Arts" to avoid revealing his true ability. His mother is surprised by his dual affinity for fire and wind magic, a rare talent.
Three days later, Ox is eager to learn magic. His mother, Fal, tests his magical power, which far exceeds expectations, shattering the measurement crystal. She then begins his first magic lesson, teaching him "Wind Cutter." Ox, recalling his past life and his promise to his dying father, dedicates himself to mastering his new life. He practices his wind magic in the forest and accidentally drops the pocket watch from the goddess, which opens to reveal an angel named Michael, who becomes his support.
Michael explains that the goddess Iria summoned him to help him prepare for the impending crisis: the revival of a "World Enemy" (the Demon Lord) in fifteen years. Ox is destined to become a lord and must prepare to defend his territory. Michael suggests finding allies to ease his burden. Ox agrees and asks Michael to call him "El."
Ox needs a reason to leave the mansion to search for allies. El suggests a "visitation" as a plausible excuse, offering to use magic to deceive anyone suspicious. Ox, however, is hesitant about using mind-altering magic. He returns to the mansion and directly asks his father, Rein, for permission to go to town. Rein, surprisingly enthusiastic, provides Ox with disguise clothes. El communicates telepathically with Ox, offering assistance. Ox chooses his disguise, and Rein summons the head maid, who swiftly dresses Ox in his new attire.
Ox, now disguised as an ordinary child, leaves the mansion, eager to begin his search for companions.
