I took the name Ronin about 13 years ago, it is now used for my pseudonym whatever I'm doing in one form or another, eg:a_ronin, realronin. The actual character, besides my D&D Barbarian, was in a book called the Sunset Warrior. There are 3 books in the set, and it is called, *duh* The Sunset Warrior Trilogy. The author is Eric Van Lustbader, and he is one of the first Fantasy authors I had read at the time. He writes mostly Japanese genre fiction, but I don't believe he's done much fantasy since then. If you want to, please pick up one of the books in the series, and you won't be disappointed, but you really should start with the first one...*g*
By the way...There is a new movie out called Ronin, with Robert Deniro in it. It looks OK, but I am concerned with the amount of people that may begin calling themselves Ronin, online...*g* Just remember Ronin doesn't look favourably on impersonators. (laughs)
There are a link or two going to the Ronin Movie here, please feel free to go and have a look at some of the pics and trailers.