Tales of the Otori by Lian Hearn : you've got Love, action, mystery, fantasy and it's set in a fictional world based on feudal Japan. So you'll be more into a japanese-like culture. It's a saga, there are 5 books, all of them incredible. Did I fail to mentiion that the love story is awesome and moving ?
And just because it's not the real Japan doesn't mean it's absurd. The author really knew what she was doing, it's really well researched.
You also have Genji Monongatari (The Tale of the Genji) which is a classic of Japanese litterature. It's a love story set in the Imperial Court, and has been adapted into a movie recently.
here is the movie's MDL page :
Genji
Interesting story behind that book : it is considered as the first novel ever written in Japanese, and it was done by a woman. Plus, it was entirely written in Hiragana, because hiragana was the only way of writing taught to women at that time (they thought a woman couldn't handle Kanjis because it was too complicated.)