The story begins with Hayato Katsuragi finding himself in a void of darkness, where he is greeted by a beautiful, talkative goddess. She reveals that he died saving a woman from a speeding car and, due to his significant good deeds, he has the option to be reincarnated with his memories intact. The goddess grants him the ability to grow stronger through effort and the capacity to understand languages.
Hayato is reborn as Reivert Runewalker in a world with a medieval fantasy setting. He discovers he has incredibly beautiful and powerful parents: Sieg, the Frontier Count of Runewalker, and Eris, his first wife, a skilled mage. He also gains a loyal cat-eared maid named Chloe. Reivert's early life is characterized by the typical experiences of an infant, including the embarrassment of being cared for by Chloe and Eris. He learns that the Runewalker territory is strategically important, bordering a hostile nation and adjacent to a dangerous "Demon Land" teeming with monsters. His father, Sieg, inherited the title after his own father died during a monster horde.
As Reivert grows, he begins to train rigorously, driven by his parents' expectations and his own desire to avoid his previous fate. He learns various combat and magical skills from his family, including spear fighting from Sieg, magic from Eris, and swordsmanship from his older half-sister, Aeris, who is exceptionally talented. He also acquires the "Genius Mage" title, mirroring his mother's abilities.
A significant turning point occurs when Reivert, at the age of one, undergoes a status assessment at a temple. His stats are revealed to be surprisingly average, except for two unique titles: "Goddess Astel's Observer" and "Limitless One," which indicate potential for immense growth through effort and a connection to the goddess who facilitated his reincarnation. He also receives the title "One Who Faces Hardship," foreshadowing future challenges. His parents, initially concerned by his seemingly ordinary stats, realize the true potential granted by his titles, especially after receiving a message from Goddess Astel explaining that his skills can also grow without limit.
The narrative then shifts to Reivert's childhood, highlighting his training and the growing threats to the Runewalker territory. By the age of eight, Reivert is a capable fighter, though still outmatched by his older sister Aeris. The story culminates with the ominous ringing of bells, signaling the imminent arrival of a massive monster horde from the Demon Land. Reivert's father, Sieg, along with Eris and Aeris's mother, Eileen, prepare to defend the territory, while Reivert is tasked with protecting the younger children, including his sister Philia and Chloe's daughter, Crona, should the worst happen. This sets the stage for a major conflict and the realization of Reivert's "hardship" title.
