The
serial first appeared in a Japanese
newspaper between 1937-39. This makes it even more interesting, I think, coming at a time right before the peak of Japan's power in
World War II. Japanese culture at the time was propagating a
myth of itself as being destined to rule at least all of Asia - the
rising sun being the dominant image. This myth was believed by most ordinary Japanese at the time, and most were willing to die for it. Those who could not go to
war felt deprived and left out. A prime, if extreme, example of what this kind of culture can do to someone who survives it is the life and death of
Yukio Mishima.
Although "Musashi" does not seem to directly propagate the aforementioned myth (so far - I'm 600 pages through), it does provide an excellent window into part of the national psyche of the time.