From publisher blurb:
Ersa (called "Nanji" by its natives) is the southern continent of the "known" world of Ert (interestingly, the name of the planet is pronounced the same in all languages). Nearly all of its land mass is occupied and controlled by the Empire of Heaven (Tengoku no Teikoku), a land of oriental character. Three additional areas on the continent are worth noting. The first is a foothill region backed by mountains to the coast occupied by savage hill tribes, known as Ryuu no Ashi Yubi. The region is not of particular interest to the Empire and efforts to subdue it have failed due to the defensible nature of the terrain and the fierceness of the "Crazy Flints." The tribesmen are of different racial stock than the Empire soldiers being larger, stockier and stronger. They mostly resemble the peoples of Ropa (Iryou Hin), but are generally darker and more hirsute. A few gnomes (bogi) also live free in this region. The second is an area underneath a portion of the Idai na Nanji Sabaku (Desert of Despair) which houses a small gnomish nation of "freedom fighters," the Jiyuu no Shakai or “Society of the Free.” They work mostly to destabilize the Empire. They have been at it for centuries and have yet to be discovered. They constitute only a minuscule portion of the total gnome population of Ersa, but have never given up hope. The third is The Dragon Teeth (Doragon no Ha), a mountain range which is considered cursed by the Empire and home to the Eldritch Hobbits or Dracolings (Doragon no Hitobito), the dragonmasters of Ert. This small, long-lived population has a symbiotic relationship with the crystal dragons, a species unique to Ert.
The Empire of Heaven is the oldest of Ert's human civilizations still extant. The current emperor is 159th in his line, unbroken since the Empire was founded. Empire territory occupies most of the Ersa continent. Succession is controlled by the priest sect, but the heir is always a direct descendent of the Emperor. This is guaranteed by the practice of royal polygamy. This practice is restricted to the Emperor and daimyō, though other nobles commonly kept yūjo (courtesans) and in certain circumstances their offspring could inherit. The Empire is not a theocracy. Though priests control the succession and the Emperor is considered holy, they wield no other organized power. At an earlier date, when the Emperor had more bureaucratic power, sixty provinces were established, each governed by a kokushi. After a time, the power in the provincial system was supplanted by militarily powerful lords. The Abijana Shogunate established the han system, the granting of fiefs to loyal samurai. A daimyō rules each han. Size was important, the most powerful daimyō controlling several thousand koku (about 150 kilograms of rice production). The smallest han is 10,000 koku, so a sizeable han might span two or more provinces. The daimyō are split into several political parties and the Emperor will charge one daimyō, the seii taishōgun, to organize a government. Coalitions are formed and political intrigue is constant. The daimyō very rarely attend court, including the seii taishōgun, instead sending professional politicians, known as the shikken, to attend to their matters of state. So, the office of seii taishōgun is usually administered by a professional politician.