I think the movie you are referring to was called Sho-Gun. I read the book and watched the movie many years ago. Both were great. I just bought my oldest son a copy of the book, because he is such a fan of that Tom Cruise movie "The Last Samurai" and has recently taken up reading.
I also thought of this (Sho-Gun) book while reading this excerpt from this new book. I think I may be hooked also !!!