Civilization is a complex concept that involves behaviors like urban development, symbolic communication, social stratification, and a perception of a separation from nature. While there are numerous species that exhibit one or more of these behaviors (e.g. bees can communicate and have a social order; termites build giant termite-sized cities underground), and a multitude of sentient species, only a small handful have evolved to exhibit all of the behaviors that are commonly understood as civilized.
Six species dominate the political landscape of the world of Eturo: hanyō, humans, kitsune, kōchū, kotengu, and urokobito. Collectively, they are known as the ascended species.
In the Land of the Crane, the distribution of species is largely the same as it is world-wide. Humans dominate and kitsune are common, but urokobito are considered outsiders, so they are underrepresented compared to the global distribution.
In the Hordelands, on the other hand, urokobito are the dominant ascended species and humans are uncommon.
Urokobito are most common in the south of Tsurukoku, where it borders the Hordelands, while kotengu are more common in the north due to the mountainous terrain. Kōchū tend to live toward the center of the country, near the regions that are more heavily forested.
Each species has ethnic variations that are a result of adapting to multiple environments as they spread across the world. Humans, for example, originated on the continent of Nyasi, where their dark skin and hair shields them from the sun. Lighter skin tones emerged as humans spread throughout the other continents and moved further from the equator, reducing their dependency on melanin for protection.
Within Tsurukoku, ethnic variations from elsewhere in the world are most likely to be encountered in large, cosmopolitan cities or where the Land of the Crane borders other lands. For example, species from all over the world are found in the capital city of Ito on the western edge of Tsurukoku. Xin and Rajput are more likely encountered in the east, near the Tsuchitora mountain range, and Naari in the northwest.