Looking for books influenced by samurai philosophy

I've been reading about Bushido and the moral code of the samurai, and I'm fascinated by how these principles like honor, loyalty, and discipline translate into a modern context.

I'm looking for fiction where this philosophy is a core theme, not just a historical setting. It could be a classic like Musashi, or even a modern novel where the characters grapple with these ideals.

Any recommendations for books where the spirit of the samurai, rather than just the sword, is central to the story?