The story begins in the Dark Temple, where a powerful Demon Lord is about to deliver a final blow to a severely injured Sage. The Sage, who fought alone against the Demon Lord, reveals his true intention: to activate a divine magic called "Reincarnation Formula." As a sacrifice, he offers his own body, blood, and magic, along with the lives of a thousand upper-rank demons, the last of which is the Demon Lord himself. The Sage successfully activates the spell, causing the Demon Lord to disintegrate and a massive magic circle to appear. His goal is to be reborn with his memories intact, hoping for a leisurely and comfortable afterlife.
The Sage is reborn as Eddie, the youngest son of the Radcliffe Marquis family. On his sixth birthday, his past memories flood back, causing him immense physical and mental distress. He recalls his past life as a powerful Sage who saved humanity and his desire for a peaceful, enjoyable next life. Eddie's current body is physically weak and has no magic aptitude, as his past self ensured a gradual memory return to protect his current psyche. He discovers his status screen shows him as Level 1 with minimal stats, but his magical ability is inexplicably high due to a "Reincarnation Bonus."
Driven by the need to acquire magic, Eddie ventures into the nearby forest. He encounters a weak Red Slime and, using his past knowledge, defeats it with a sharpened stone. This allows him to learn Fire Magic (Weak) and Detection Magic. His status screen updates, revealing a surprisingly high "Magical Ability" score, far exceeding his previous life's capabilities.
Suddenly, Eddie hears a scream from deeper within the "Forbidden Forest," a place his family guards. Using his newly acquired Detection Magic, he discovers a group of Orcs attacking a lone, injured girl, identified as a "Princess Knight." Despite his resolve to live a life solely for himself, Eddie feels compelled to intervene. He rushes to the scene, finding five dead knights and eight Orcs, including an Orc King, cornering the Princess Knight, Clarice.
Eddie decides to use his Fire Magic to distract the Orcs and escape with Clarice. However, his first attempt unleashes an incredibly powerful blast of fire, instantly incinerating the Orc King and the other Orcs. This display of power, far beyond what a Level 1 child should possess, shocks everyone, including Eddie himself. Clarice, bewildered but grateful, scoops up Eddie and flees.
As they escape, Eddie uses his magic again, this time with more control, to eliminate the pursuing Orcs. He is then accidentally crushed by Clarice when they both fall. After tending to Clarice's injuries and the fallen knights' bodies, Eddie learns he has acquired Wind Magic and Sleep Magic from the Orcs. He uses Sleep Magic to incapacitate Clarice temporarily so he can discreetly transport the knights' bodies outside the forest using Wind Magic, avoiding further complications.
Returning home, Eddie is met by his worried mother, who is distressed by the events. He fabricates a story about practicing magic in the forest, which his parents, overwhelmed by relief and pride in his newfound abilities, readily accept. They are astonished by his power, but their primary concern is his safety and well-being.
Later, Clarice awakens and, after being informed of the situation by Eddie's parents, requests to speak with Eddie alone. She reveals she is the third princess of the small kingdom of Maily and had come to protect the prophesied savior. She suspects Eddie is the savior, not a chance encounter. Eddie, wanting to maintain his peaceful life, agrees to keep his true power a secret, and Clarice, touched by his bravery, promises to protect him.
Ten days later, Eddie attends a magic aptitude test at the Royal Academy. To conceal his immense power, he uses a prepared paper with his brother Max's low aptitude score. However, the magic testing device malfunctions, printing an impossibly long list of all known magic types, indicating an SSS aptitude. The teachers are in an uproar, but Eddie quickly presents his brother's paper, convincing them it was a malfunction. He successfully enrolls in the lowest class, F, ensuring his quiet life.
