"Even if we should get home, you know very well you can't be. You weren't born into a samurai family. You were born a fisherman's son and you will be a fisherman, and any sons you have, they also will be fishermen. That is the way it is; that is the way it has always been; that is the way it will always be." (1.2.33)
Even Goemon doesn't believe that Manjiro can become a samurai. Every one of Manjiro's friends is a traditionalist, all into the strict divisions between classes in Japan. That makes Manjiro more alone, but also more unique among the guys.
"If you were a real samurai, you would commit seppuku now, rather than wait to be humiliated by the barbarians," Goemon said.
"Maybe they won't humiliate us," Manjiro said hopefully.
At this, Goemon simply grunted. (2.3.45-47)
Goemon's looking down on the "barbarian" rescuers because they ask the boys to sit on benches instead of sitting cross-legged. It's really a potato, potahto kind of issue, though, when we get down to it: Every culture has their own norms.
And it was like a village, they thought, as they were swept on board the John Howland and through a series of small rooms, like tiny houses, each one more ornately decorated than the last.
"Only someone very important could own rooms like these," Goemon whispered.
"Maybe even a shogun!" Manjiro gasped. (2.3.32-36)
The guys are pointing out something that's true even on the supposedly classless, equitable American ship: There's still an implicit difference in class, as the guys notice through the different levels of decoration in the rooms. As you might expect, the stateliest, most well-appointed room on the boat is Captain Whitfield's.
"I feel it is important for me, as the leader of our group, to watch out for you. Now, listen to me. It is better for you to stay away, so that you don't become tainted by their ways. They are corrupting you. Already you walk with their swagger. You are forgetting your manners and addressing all of us as your equals. You neglect to bow. Just now—you did not acknowledge me. You don't even bow to the captain of this ship!" (2.5.35)
Denzo's speaking to Manjiro, so we know there just has to be trouble. But doesn't it seem that Denzo's trying to power-trip all over Manjiro?
"We are just humble fishermen. Only big important people—the shogun, the daimyo, maybe this captain—they can do great things."
"That's what I used to think, too…." (2.8.33-34)
Goemon's all about sticking up for the old Japanese ways, even if it means that he—as a fisherman—gets the short end of the stick. But Manjiro's not down with all of that. What he goes on to suggest to Goemon is nothing short of a class revolution, even if Manjiro isn't thinking or speaking in such dramatic terms. He is advocating some dangerous thoughts for Goemon, though, so it's no wonder Goemon's scared that Manjiro's already lost his way. Upending the status quo is often an unpopular thing to do.
"Why would he do a kindness to me?" Manjiro asked.
"Why shouldn't he?"
"Because I am just a boy and he is a grown person. I am a poor nobody and he is a rich important person."
"And why can't a rich man be kind to a poor 'nobody'?" (3.15.31-34)
Captain Whitfield is referring to a common principle of helping a fellow man. This principle can only work if based on two contradictory ideas, though. First, Captain Whitfield is showing the impulse toward a classless society, where poor and rich shouldn't have such a huge social division. However, the dialogue also shows how class division has to exist in order for the principle of common goodness to exist. How can there be a principle of being good to the common or fellow man if there wasn't an unfair situation that requires the need for principle to exist in the first place?
"Look how that woman walks with her arm on that man's arm. Don't they know that they shouldn't touch in public—that's just wrong! And, besides, women should always walk behind men."
"Why should women walk behind men?" (9.10.23-24)
It looks like Manjiro's sympathies have extended to women, the true absent class in the book. Well, it's not totally absent, but the female presence is definitely lacking in this book in a major way. Not that there's much that can be done about it—the story does have (at this point) to do with a ship at sea in the 19th century, which isn't exactly a female sphere at this time. This just makes Manjiro's response even more radical, though, since he's questioning the patriarchal system that overarches American and Japanese cultures.
"It's wondrous what they do," Terry said breathlessly. "It's so exact, it's almost more real than looking in a mirror. And fast! Not like sitting for days or weeks to have your portrait painted—and who can afford that, anyway?" (4.34.8)
Terry definitely has a point: Sitting for a portrait for weeks on end definitely couldn't work unless you had money. Good thing photography isn't just for the wealthy these days.
He paused, not wanting to disturb them, and heard the captain say, "I had resigned myself to a life at sea, with a small house in Fairhaven for my few months between ships. But now, with a bright young ward, I've begun to think of a farm again. A boy should have land to roam, work for his hands to do, a pond to fish, and a horse to ride."
Who was this boy they were talking about? Was it him? Was the captain suggesting that he should have a horse to ride? (3.15.48-49)
The Captain's telling Mr. and Mrs. Aken that he's thinking about changing his lifestyle for Manjiro. This is also one of those subtle moments when we realize how well-to-do Captain Whitfield must be. He definitely doesn't flaunt his class or wealth, but the easy way he just drops the idea of buying a farm and a horse for Manjiro is telling.
"But others say," the messenger continued, "that Lord Yamauchi wants him to teach young samurai the barbarian's language." The man lowered his voice to a whisper. "They even say that he will be a samurai himself." He clucked his tongue. "Imagine—a simple fisherman becoming a samurai!" (5.41.15)
So this would be a big change, right? Manjiro going from fisherman's son to samurai in Edo period, Japan. Even though the messenger doesn't know what will happen, the fact that it's even a rumor that Manjiro might become a samurai is a big deal. This is a sign of change in its own right.