Heart of a Samurai may be all about how a young Japanese guy changes the fate of Japan (and America) in the 19th century, but the book also shows how huge transformations (in society and in the protagonist's life) can only come from a constant, principled, stable character. Our protagonist may have a totally dramatic life-story, but he's about the least dramatic main character you can imagine. Which is important because he's like a rock in the middle of a bunch of major social changes.
Questions About Change
How does Manjiro change and stay the same as a character?
How does Manjiro's character compare to all the events that go on in the novel?
How does technology introduce change into both America and Japan in the 19th century?
Is change a good thing in the book or is it instead simply inevitable?
Chew on This
Manjiro doesn't actually impact Japanese society in the 19th century all that much; the Americans have a greater impact than he does.
Technology is really what changes everything in the novel.