oh shit never realized the guy who played ichi the killer (2001 movie!) is the same actor who played yabushige
finished the book this weekend, fucking awesome. 100% recommend to anyone who loved the show but wants more, and it really helped flesh out a lot of details for me. For example I felt Toranaga's motivations were a bit flimsy in the show, yeah becoming Shogun is cool and all but his older son is dead so it won't really last long.
But there are way more characters in the book and the legacy of his moves makes WAY more sense, especially with a character introduced late who completely changed the way I saw Toranaga. You also get a lot more world politics talk, Toranaga talk, Regents politics, Christian plots, and a key plot point involving the Emperor is completely excised from the show.
Be interesting to see how the show shakes out in the next few years on prestige TV lists, I'd have to rewatch to really figure it out but I'd put it maybe above Mad Men and Breaking Bad right now, probably below Wire and Sopranos. Not sure about stuff like Chernobyl, Arcane, Succession, etc.