In a world locked in a brutal, decades-long war between humans and demons, the
legendary Hero abandons his army to infiltrate the demon realm single-handedly, determined to assassinate the Demon King and end the bloodshed. Upon breaching the inner sanctum, he discovers the Demon King is not a monstrous tyrant, but a brilliant, busty woman known as the Crimson Scholar. She stops him with cold logic, arguing that a sudden assassination would plunge both societies into catastrophic chaos. She explains that the war actually unites the fractured human kingdoms and stabilizes the demon economy, meaning peace requires a meticulously engineered, gradual societal revolution. Convinced by her vision, the Hero agrees to become her champion and husband in a sham
political marriage.Operating under the alias "Maou," the Demon King establishes a secret agricultural academy in the human realm, utilizing advanced knowledge of crop rotation, potato farming, and economics to alleviate widespread poverty. Meanwhile, the Hero travels incognito, protecting vital supply routes, resolving local conflicts, and earning the trust of various factions. Their partnership drives massive agricultural and industrial reforms, directly challenging the oppressive monopoly of the Church and the corrupt nobility, who desperately want to maintain the status quo of eternal war.As their influence grows, so does the romantic tension between the socially awkward Hero and the pragmatic Crimson Scholar, though their work always takes precedence. Their progressive economic model sparks an industrial boom, but it also triggers a massive backlash. The powerful Church brands them as heretics and mobilizes a massive crusading army to crush the burgeoning innovations and eliminate Maou.Facing impending doom, the Hero unites disparate human nations, rebellious nobles, and even factional demon lords into a cohesive coalition. The climatic conflict reaches a boiling point at the Battle of Winter Palace, where human and demon armies fight side-by-side against the zealous Crusader forces. Utilizing advanced tactics, economic leverage, and sheer martial prowess, the coalition shatters the Church's monopoly of power. In the aftermath, the old feudal order collapses, clearing the path for an unprecedented era of enlightenment, trade, and fragile coexistence. Having successfully laid the foundational blueprints for a peaceful world, the Hero and the Crimson Scholar step out of the shadows, ready to guide humanity and demons toward a joint destiny, proving that knowledge and cooperation are far more powerful weapons than steel and fire.