The story begins in the grand capital of the Gastoro Empire, a nation with over a thousand years of history. The Imperial Palace, a symbol of its power, is surrounded by districts for nobility, administration, and entertainment. Amidst this opulence, a new cohort of twenty-four elite officer candidates are being appointed. Among them is a black-haired youth named Heizen Heim, who, to the shock of his peer Emma Dona, expresses his disgust at the perceived corruption with a remark about a "rotten smell." Emma, a former academy classmate, is mortified by his inappropriate outburst, urging him to remain silent.
Heizen finds the lengthy introductory speeches by high-ranking nobles to be a waste of time, serving only to appease superiors rather than genuinely welcome the new officers. When the new officers' speeches begin, Emma notes that she expected Heizen to be the top-ranked candidate, but he claims third place was his strategic goal. The narrative reveals a systemic bias in the officer examinations, which are ostensibly merit-based but have historically seen no commoner reach the top two positions, with chief positions always held by members of prestigious noble families. Heizen, a commoner, achieved third place, the highest possible for his station, as a calculated move to secure a starting position within the empire's core.
The assignment of positions follows, clearly favoring those with higher noble titles, who are assigned to prestigious posts like the Imperial Palace Guard. Heizen, a commoner, is assigned to the Northern Garna region, a dangerous border area adjacent to the hostile Diord Public, and a frequent site of conflict with the nomadic Kumin tribe. This assignment is perceived as a punitive one. Heizen is met by his friend Kakuz, a formidable warrior from the Zexan tribe whom Heizen had hired as a bodyguard. They are joined by Dometa Keas, a noble who mocks Heizen's assignment, prompting a sharp and cutting retort from Heizen, who dismisses Dometa and his ilk as lacking true merit.
Heizen arrives in the Northern Garna region, a stark contrast to the capital, characterized by a functional, unadorned fortress. He is introduced to Colonel Zilva Magno, the commanding officer, who notes Heizen's commoner status and assigns him to the Eighth Platoon, a unit described as a "band of ruffians." Heizen learns that the platoon is under the command of Sergeant Chomo, as the higher-ranking officers have met unfortunate ends. Heizen immediately asserts his authority by physically punishing Chomo for disobeying an order, demonstrating his ruthless adherence to military discipline. He then imposes a rigorous training regimen on the entire platoon, emphasizing physical conditioning and obedience.
The following days see Heizen implementing strict training, focusing on speed, endurance, and combat skills. He establishes a system of merit-based rewards and punishments, ensuring that all soldiers, regardless of rank, are held to the same high standards. He also begins to gather intelligence on the region's threats, including the Diord Public and the Kumin tribe, by tasking a soldier named Edal with compiling detailed reports.
A tense encounter occurs when Lieutenant Colonel Mospizza, Heizen's superior, confronts him about the deaths of two sergeants, Chomo and Dickett. Mospizza accuses Heizen of failing to report the deaths and questions his actions, implying a lack of remorse. Heizen calmly defends his actions, citing military regulations and the evidence of attempted poisoning. He also highlights the negligence of Mospizza and other superiors in addressing previous suspicious deaths within the Eighth Platoon, effectively turning the tables on his accuser.
The narrative then shifts to a dream sequence where Heizen, in a past life, reflects on his death as a powerful mage and his subsequent rebirth in a younger body three years prior. This revelation explains his unusual demeanor and unwavering resolve.
The story concludes with the Eighth Platoon being dispatched as a vanguard to defend nearby villages against an incursion by the Kumin tribe. Heizen, demonstrating his strategic acumen and leadership, quickly assesses the situation, identifies a potential enemy mage, and plans a decisive engagement. He emphasizes speed and efficiency, leaving his subordinates to follow his lead.