Legend of the Five Rings (often abbreviated "L5R") is a fictional setting that covers in detail the fantastical land of Rokugan, a nation whose culture and history is based on that of feudal Japan. The setting also briefly touches upon many of the different cultures that occupy the same world. This world is the foundation for the Legend of the Five Rings Collectible Card Game, the Legend of the Five Rings Role-Playing Game, the Clan Wars miniatures game, and a series of novels. Legend of the Five Rings was also the "featured campaign setting" of the Oriental Adventures expansion to the third edition of Dungeons & Dragons, but this book and the line of L5R material based upon it is now out of print.
From L5R Wiki