The Empire's Female Marshal: From the Start, I Arrest the Crown Prince's Grandson

In the year 320 of the New Era, human society has regressed to the “Great Ye Empire,” where constitutional monarchy coexists with powerful feudal clans. Though set in the future, the story must contain no science-fiction elements such as mechs, AI, or lasers. Society resembles a fusion of the Republican era and ancient China, with cold weapons and old-fashioned firearms existing side by side under a rigid class system.