>>/51857/
Ah I wrote a reply yesterday but apparently did not hit new reply.
So.
Yeah the novel is a novel, albeit a historical one, with real historical background (the end of the sengoku period), and with real historical figures with their names twisted a bit (Tokugawa -> Toranaga). Even the English pilot was a living person.
The historical setting, the customs and costumes, the buildings and whatnot feels believable. I can't really go into splitting hairs that "they didn't wear those swords with those dresses" or whatnot.