William Adams was the real life inspiration for Anjin in Clavell's novel Shōgun. Adams was an English pilot on a Dutch expedition to Japan and the spice islands that went via the Pacific. His ship and a small number of surviving crew washed up in Japan. Adams learned the language, the etiquette, and found a place in the court of first Shogun.
The book focuses on him and a group of English traders that show up a few years later to establish a trading "factory". Milton uses their diaries and letters to tell the interesting story of this period of European-Japanese interaction.
Milton uses a lot of direct quotes, and in spite of his modernizing some of the language, I found it heavy going in places.

Left in the Little Free Library