Episode 7 (spoilers)
The show keeps on diverging more and more from the source material. Blackthorne is given nothing to do in the TV show after messing about with the cannon for a little while, but in the book he is assigned 200 samurai. The Jesuits are remarkably absent lately this late in the story.
Buntaro requests permission from Toranaga to kill Blackthorne, as he does not like the way he looks at his wife, In the book Buntaro had no such reservations about his wife and the pilot. Toranaga of the book knew he would need to have Buntaro killed if he ever suspected that the pilot was sleeping with his wife. Toranaga valued Blackthorne more than Buntaro.
The TV show does not even hint at an affair between Mariko and the pilot other than the one night after they moved in together in Ajiro.
Naga attempts to kill Saeki Nobutatsu, but fails. This was not in the book.