Accompanied by his skilled assistants, the 'Realist Hero' Kazuya Souma keeps pushing to revitalize the Elfrieden Kingdom via governmental overhaul. After successfully seizing Van—the capital of Amidonia's Principality—Kazuya now confronts an envoy from the Gran Chaos Empire, demanding retribution for violating the war prohibition set by the Mankind Declaration Treaty. Though the circumstances are bleak, Kazuya identifies a route that avoids needless battle while securing fresh allies. With his strategy appearing flawless, the sole obstacle to triumph lies in obtaining the envoy's endorsement in the complex political arena and negotiations.