Kara-Tur is a far-eastern campaign setting for Dungeons and Dragons, created by David Cook in the first edition splatbook Oriental Adventures. It was almost immediately retconned into the Forgotten Realms setting, as is the fate of all things. The setting was never really updated for 4e, although it did get an entire issue of Dragon Magazine dedicated to the area, and as of yet nothing has been forthcoming for Dungeons & Dragons 5th Edition besides a brief mention that it might be where a PC from far away originally hails from.
The setting comprises a healthy collection of far-east historical periods, including warring states period Japan (Kozakura), Imperial China (Shou-Lung, complete with Great Wall and Triads), and the lazily named Tabot (a holy-child-monk-emperor worshipping mountain theocracy). It even has a shitty-wall hating, loose collective of steppe horsemen (although not as yet a grand uniter of clans), who even got their own spin-off sub-setting called The Horde.
Kara-Tur is built with China and Japan in mind, but each nation divided into two to create an adventure environment based on specific time period and theme.
- Shou Lung is an empire representing the stable periods of China with a bureaucracy and Emperor...also showing them as "good China" as almost all bureaucrats and the Emperor are non-evil alignment.
- Tu Lung is another fantasy China who broke off from Shou Lung and show off more chaotic periods of real-world Imperial China...except the aristocrats and Imperial Family being downright evil and entire kingdom being rebellious and war-torn that the one wonder why Shou Lung or other neighboring kingdoms hadn't taken over.
- Wa is the Tokugawa Shogunate, complete with a military dictatorship ruling in lieu of Emperor and the chronic issue of unemployed Samurai after unifying the warring clans.
- Kozakura is Sengoku-era Japan--also Kamakura era due to inclusion of retired Emperors ruling behind the scenes and series of regents being the power behind both the Shogun and the Emperor--where the feudal Daimyos fought against each other yet strangely had to no historical connections with Wa despite using Japanese aesthetics and terminology.
Later on, when Kara-Tur was added to Forgotten Realms--which Ed Greenwood dislike the addition due to its near-historical analogues being out of place and arguments over whether historical aspects made sense within Toril--where they added Tabot (Tibet), Koryo (Korea), Bawa (Indonesia), and Malatra...which is copy-paste version of their real world counter part that Koryo is basically taken straight from Korea's Three Kingdoms and later Korea unification under Silla in Dragon Magazine's update.