We're tempted to say that River of Stars is "based" on Song Dynasty Chinese culture, but that's not quite accurate. While Kay has meticulously researched the period, he creates incredibly diverse people from around the country of "Kitai," which make the notion of a singular culture or nation silly. There's Ren Daiyan, the brave outlaw who infiltrates the army and rises through its ranks, and his buddy, Zhao Ziji, a romantic thinker who buys too deeply into every calling in life, be it government work, war, or highway robbery. There's Lin Kuo, a scholar who so wanted a wise child that he raised and educated his daughter like a boy, and Lin Shan, Kuo's daughter, whose education leaves her particularly critical of the misogynist establishment, and later, estranged by the war it creates. We even meet the Prime Minister, his son, and the emperor himself, that last a fascinating introduction of a privileged soul deluded with visions of his own generosity and heart. The cast give us the rural life, the poetry and art, the politics and military motions that are irreconcilable with each other. There's no such thing as a culture for a country that big. There are bandits who can become heroes in wars that scholars will only ever hear and write third-hand poetry about.
