The actor, along with co-star Anna Sawai, revealed how the story was changed.

Shōgun has become the new epic historical series that has taken the world by storm with its breathtaking depiction of Japan’s beautiful landscapes and the brilliant characters that it employs to tell its story. The series is based on a novel written in 1975 by James Clavell and is much more complex as opposed to what the show depicts.
Anna Sawai and Hiroyuki Sanada in Shogun
The book has been adapted once before in the 1980s in the form of a miniseries and follows the perspective of a white man in Japan. The series that has been adapted on the screen does not follow the entire book down to the T and commits some character arcs in favor of a streamlined structure. Actors Anna Sawai and Hiroyuki Sanada talk about the idea behind adapting the book the way they did.

Anna Sawai mentioned why some parts of the book were chosen

Anna Sawai in Shogun
Anna Sawai of Monarch fame has been able to carve out a very healthy niche in Shōgun. With her character serving as the bridge between two worlds, Sawai, when asked about how much of the book have they covered, responded clearly about the way in which the book was adapted, speaking to the AV Club. She said:

“We do cover the whole book in season one. But it’s so beautifully written and detailed, we had to choose the key moments to show in our 10 episodes. So there’s war, passion, politics, loss, love, real human drama.”

To this, Hiroyuki Sanada quickly agreed with a “Yeah, it’s all in one.”, talking about how the show adapts the entire book while leaving out some complex bits for the benefit of pacing and streamlining the story.

Shōgun has taken the world by storm with their breathtaking storytelling

Hiroyuki Sanada in Shōgun
Shōgun has become a worldwide sensation, thanks to its breathtaking cast, gorgeous set pieces, and a story that has a fresh take on a trodden story idea. Modeled after the wars of the unification during Japan’s Warring States period, the story focuses on the core themes of the story and streamlines a pretty fleshed-out novel in a lean but tender storytelling experience, one that ushers in yet another epic in the same vein as History’s Vikings.

With a hardworking cast with the likes of the legendary Hiroyuki Sanada, Anna Sawai, and Cosmo Jarvis, the actors, especially Anna Sawai, have gone above and beyond to immerse themselves into their roles. In a way, the fruits of their labor have managed to not only make it to the screen, but resonate with a large section of the audience, who are eager to see what happens next in the story.