When their light-elf brethren began a brutal purge against them, the dark elf chieftain Dinerúth Andariel was forced to flee her homeland with her surviving people. After wandering through hostile lands, the refugees stumbled into Orcsen, a unified nation of multiple races led by orcs, a species traditionally viewed as barbaric monsters. To Dinerúth's surprise, King Gustav Falkenhayn welcomed the dark elves into his kingdom, offering shelter rather than violence. In exchange for weapons and medicine to rescue more of her kin, Dinerúth swore a blood oath to the orc king, forming an unlikely alliance that would reshape the world.

The world of Orcsen defies traditional fantasy conventions. The age of swords and chivalry has passed, replaced by an era of gunpowder, steam engines, and industrial warfare. Magic still exists, but it now competes with rifles, artillery, torpedoes, and ironclad ships. This setting mirrors Earth's history from the Russo-Turkish War through the early twentieth century, complete with railways, mass production of steel alloys, and modern military logistics. The continent itself bears scars from a celestial catastrophe, with twelve moons orbiting the planet and impassable seas created by an ancient satellite collision that reshaped geography.

King Gustav stands at the center of this transformation. Unbeknownst to his subjects, he is a reincarnated human from modern Earth, brought into this artificial universe created as a fantasy simulation by an advanced civilization. Over 120 years of rule, he used his knowledge of history, agriculture, engineering, and military strategy to drag the orcs from tribal barbarism into an industrialized nation-state. He can manipulate weather through incantations in his former language, a power his people call Divine, but his true strength lies in logistics, diplomacy, and preparing victory before battle begins. Under his leadership, Orcsen became a multi-ethnic power where giant wolves, kobolds, dwarves, and great eagles live as equal citizens, their national law forbidding the consumption of other sentient species.

The narrative unfolds across several major arcs. The initial arc focuses on Dinerúth's escape and the forging of the orc-dark elf alliance. She becomes the commander of the Amphangria Brigade within the Orcsen military, struggling between her desire for vengeance against the light elves who slaughtered her people and her growing loyalty to Gustav and his kingdom. The second arc escalates into total war against Elfind, the ancient elven kingdom. What begins as a rescue mission transforms into a campaign of annihilation, with Orcsen deploying modern tactics, mass-produced molybdenum steel weaponry, and overwhelming industrial capacity against the vainglorious but technologically stagnant elves. Later arcs introduce additional factions including dwarven naval forces and other elven powers, expanding the conflict beyond the binary orc-elf struggle into a complex geopolitical war. The narrative follows Gustav's strategic offensives, including railway-supported supply lines and surprise attacks that earn the orc infantry the fearsome nickname Orcsunami from Dinerúth herself.

Throughout the story, the series explores themes of ethnic cleansing, industrialization, cultural assimilation, and the cyclical nature of history. The elves of Elfind, having received advanced knowledge from human players over centuries, developed an extreme racial superiority complex, believing their civilization represents peace and beauty while they systematically exterminate dark elves and other races they deem inferior. Orcsen, despite its reputation for savagery, proves more technologically advanced and socially inclusive. Yet the title's question looms over everything: how the barbarian orcish nation came to burn down the peaceful elfland. The answer, the narrative suggests, lies not in inherent orcish brutality but in historical forces, political betrayals, and the harsh realities of survival in a world where peace is often just the absence of war.