Bushido is a game of a mythical feudal Japan by Bob Charet (misspelled) and Paul Hume, Published by Fantasy Games Unlimited in the 80s. It is level and class based but it only takes you to 6th level and has only a handful of classes, but lets face it, if you are going to recreate this era in Japan, you only need Samurai and Ninjas It makes a few changes to the history to allow for tabletop gaming, such as allowing non-samurai to carry one sword, only samarai can carry two. 2nd ed cleaned everything up and added more background put I never owned it and have only a passing familiarity.
Bushido is fantastic in recreating this era. but you will need to read outside the books to get a better grasp on the history. Bob's wife was from Japan so he was able to access a lot of first hand material for sourcing.
I had the pleasure or meeting Bob on more than one occasion at cons. and actually played in a Bushido game he ran (I won!) As far as I know a lot of old FGU games are still in print and second ed. might not be too hard to get your hands on.