L5R is a game played in the setting of Rokugan. This fictional, fantasy world, is a combination of numerous elements from Asian Culture. If you didn't know that already, you've got some catching up to do.
I setting is obviously most influenced by Japanese culture. The characters that you play as are highly influenced by classic roles in Japanese society - Samurai, Ninja, Monks, and Courtiers. My understanding of Japanese culture and from talking to my Japanese family, it would seem that the Spellcasting, magic side of this game, is more heavily drawn from Chinese mythology and Chinese culture than Japanese. That is in no way a bad thing, just something culturally that you should be aware of. I think they did a really good job in making it very clear that Rokugan was not supposed to be a strict copy of a real world society, but rather a fantasy setting based off of several real-world cultures. That works for me.
It is actually pretty suprising how much they took cultural realism into consideration when making this game. In one section, they happen to bring up the ideas of Sexism, and man/woman roles, in the world of Rokugan. The game itself makes allowances for female samurai, ninjas, and courtiers, but it also makes the note that if you do want to go more realistic with it, you should probably take into account the fact that these cultures had very strict definations regarding the roles of women in society.
But enough with all that noise, let's talk about how cool this setting is.
The world of Rokugan is comprised of a number of different clans who are said to have descended from the gods. On a side note actually, creation mythology in the setting is a mixture of what we are probably familiar with from Greek/Roman mythology and creation myths from Asian settings. Getting back to the world, these clans control most of the power in Rokugan and are constantly wise to threats from within their power structure as well as to threats from outside the empire. Enter the Shadowlands. The Shadowlands is pretty much the source of primal evil in the world and the great corrupting force for all Samurai.
That summary might be pretty quick, but in all honesty, it would be really, really hard to wrap the entire setting of Rokugan up into one review. Let's just say that the setting is pretty awesome. I would have liked to know more about the major clans, and a little less about the minor clans, but I do have a lot of my old rulebooks that I can consult for fluff; it's not as if fluff in this book is lacking, it's just that I would have liked more in that one particular area, mostly because I think if they had expanded that section we could have gotten a few more full color pictures out of it :P
Regardless, I would like to show of the setting a little bit more. For that reason, I am going to post here, 4 Characters that I made using the L5R Rules. These 4 Characters will come from my 4 favorite clans - Crab, Crane, Lion, and Scorpion. Those clans are just too much fun to play around with. I might even add in a Mantis clan buji if you're lucky. Stay tuned for my character posting fun.
Lots of Luck