The story begins in the divine realm, where the Evil God laments the Creator God's habit of summoning heroes from other worlds to defeat the Demon Lords he cultivates. His attendant, a Shikigami, explains that these summoned individuals become specialized classes like Heroes, Sages, or Holy Knights, easily overcoming the Evil God's creations. Frustrated, the Evil God devises a plan: he will summon a hero himself and curse their soul to prevent them from becoming powerful, thereby thwarting the Creator God's plans and consuming divine energy in the process.
The Evil God then targets Saijo Haruto, a seventeen-year-old who was just killed by a drunk driver. Haruto finds himself in the Evil God's temple, his body translucent, realizing he has died and is about to be reincarnated. He initially reacts with shock but, after hearing the Evil God's explanation, accepts his fate, albeit with a degree of resignation. Haruto, familiar with reincarnation tropes from light novels, eagerly anticipates receiving powerful skills or cheat abilities. However, the Evil God reveals his true intention: to curse Haruto with "Status Lock," preventing his stats from ever increasing, regardless of how many monsters he defeats. Despite Haruto's protests, the Evil God forcibly reincarnates him, casting a powerful, irreversible curse fueled by immense divine energy. The Shikigami notes that while they intended to give Haruto a low-level class, the Creator God's domain rules forced him into a "Third Class" of Sage, though the curse would still prevent him from becoming strong enough to defeat the Demon Lord. Exhausted, the Evil God rests, unaware of a crucial mistake he made during the curse casting.
Haruto awakens in a new body, feeling heavy and disoriented. He soon realizes he has been reincarnated as a five-year-old named Hart von Silverray, the third son of a Count in the Glendell Kingdom. His memories of his past life and the encounter with the Evil God feel like a dream, but his knowledge remains intact. His personal maid, Tina, a half-elf, attends to him. Hart discovers his status board, confirming the "Status Lock" curse, which fixes all his stats, including his Sage class at level 1. This crushes his initial plan of becoming powerful through knowledge-based cheats, especially after learning that many advanced concepts, like mayonnaise, were introduced by previous heroes.
Despite his limitations, Hart begins his training in magic and swordsmanship under Tina, who is revealed to be a remarkably powerful Level 250 Magic Swordsman, a descendant of a hero. Hart, unable to raise his stats, focuses on studying ancient runes and magic theory from his father's library. He discovers that his "Status Lock" curse might not be entirely detrimental, as his magic power doesn't seem to deplete when casting spells, suggesting an infinite mana pool. He begins practicing rapid spellcasting and experimenting with combining elemental magic, aiming to compensate for his fixed stats.
Hart's first attempt at hunting a monster, a Horn Rabbit, is successful. He defeats it with a single Fire Lance, demonstrating impressive control and accuracy. However, witnessing the creature's death deeply affects him, causing him to tremble. Tina comforts him, explaining the necessity of hunting monsters for survival and sustenance. Hart, determined not to shy away from this reality, learns to butcher the creature himself. Tina, observing Hart's actions and his ability to overcome her magic, begins to suspect he might be a reincarnation of someone she knew a century ago, a hero she has been waiting for.
Hart continues his secret training, mastering the ability to cast spells without incantation, a rare and inefficient skill that could prove useful in specific situations. He dedicates himself to improving his magic speed and power through relentless practice, driven by the desire to overcome his limitations and perhaps even prove the Evil God wrong.