The protagonist, formerly a salaryman, is reincarnated as Reis Validor, the third son of a Duke in a world reminiscent of his favorite game, "Brave Fantasy." He retains his memories and knowledge of the game, which he realizes is crucial for survival. Reis discovers that his new identity is that of a minor antagonist destined to be killed by the protagonist. His primary motivations are to avoid his predetermined fate, become stronger than the protagonist, and ensure the survival of the Validor family, which is slated to be annihilated before the game's main story begins.
Reis's immediate goals are to prevent himself from becoming one-armed, a fate that befalls the original Reis due to a monster attack, and to prevent the Validor family's downfall. He begins by leveraging his game knowledge to acquire stat-boosting rings from a wary shopkeeper in the city of Validore, a location only accessible later in the game. He notes the fear and resentment the common folk hold towards the Validor family due to their exploitative practices.
His family life is strained. His eldest brother, Life, openly despises him, calling him a "good-for-nothing." This animosity stems from Reis's inherited spatial magic, which is powerful but has a terrible mana cost, making it impractical for everyday use compared to the offensive magic possessed by the rest of his family. This perceived uselessness led to a lack of parental affection and a warped personality in the original Reis. The protagonist, however, finds his current situation an improvement over his previous life, appreciating the basic necessities and the potential for self-improvement.
Reis dedicates himself to training, practicing spatial magic with his tutor, Garing, and switching from the original Reis's sword to daggers, which had superior options in the game. He also focuses on physical conditioning, supplementing his diet with monster meat for protein. His changed demeanor, marked by politeness and gratitude, begins to soften the fear his servants once held, though his family continues to mock his efforts.
He also has an arranged marriage with Riem, a viscount's daughter. The original Reis treated her poorly, engaging in sexual harassment due to his family's higher status. Reis intends to mend this relationship to avoid future complications, as Riem is a potential heroine in the game. Their meeting is cordial, with Riem maintaining a polite, albeit somewhat distant, demeanor.
Reis's training intensifies with practical combat experience in the "Forest of Wickedness," a dangerous dungeon near Validore. He successfully defeats a goblin using his spatial magic, demonstrating its potential despite its mana cost. He learns that his spatial magic's efficiency varies depending on what it interacts with, with living beings being the most draining. His combat prowess impresses Garing, who admits he didn't expect Reis to fare so well.
The narrative then shifts to the impending arrival of Third Princess Philia, a key figure whose death leads to the Validor family's ruin. Reis is anxious, as he feels unprepared for this event. His family, however, is eager to impress the princess, hoping for advantageous marriages. During a hunting expedition with the princess and his brothers, a third-layer monster, a High Wolf, appears, overwhelming the Validor soldiers and forcing a panicked retreat from his brothers, highlighting the family's current weakness and the imminent danger to their status.
