The Twelve Kingdoms takes place a sort of medieval east-asian world that never existed, with magical beasts and gods and other fantastical creatures. Yoko Nakajima is an average high school student who is swept away by a mysterious man with long white hair into a world on the other side of the ocean. Apparently, Youko is the rightful empress for one of the twelve kingdoms, but must first overthrow the current false empress and get past those who do not wish to see a foreigner come to power.

Aside from this, there are other plot lines in the anime involving politics and society in the world. The Twelve Kingdoms has heaping piles of colorful culture, politics, social messages, and a WHOLE WORLD of characters and terms! What else can you expect from an anime that not only examines the adventures of a girl thrown into a mystical world, but also the stories of all the important people and places around her?