Most good stories start with a fundamental list of ingredients: the initial situation, conflict, complication, climax, suspense, denouement, and conclusion. Great writers sometimes shake up the recipe and add some spice.
Exposition
Lost At Sea
A small group of young Japanese fishermen get stranded at sea and then make their way to a deserted island, where they stay for a while. Their food and water are running out and they don't know what to do. Sounds like a pretty bad situation right? That is, until Manjiro—our main dude—spots a ship near the coast of the island and swims out to the ship for help.
Rising Action
The Land of the "Barbarians"
This part covers a good bit of the book only because there are so many conflicts. First, there's the fact that the rescue ship that picks the boys up is manned by "barbarians"—a.k.a. mostly white Americans. For a closed-off people like the Japanese, it's like meeting the devil. And since Manjiro and the gang have been stranded, the stakes are about as high as they get when they first encounter this American crew.
Adding to the rising tension is Manjiro's ability and desire to learn from these "barbarian" guys, especially Captain Whitfield. This puts him at odds with his pals, who just want to head back to Japan and have nothing to do with the good captain and his crew.
Climax
Manjiro makes a couple of key decisions throughout the book, so it's like the book has more than one climax.
Going to America
The first climax is all about Manjiro's decision to go to America with Captain Whitfield. Once he decides to leave all that is familiar to him, you just know nothing can possibly be the same.
And it definitely isn't. Manjiro basically becomes landed gentry in Connecticut: He works the farm, goes to school (a first for him), learns to ride his own horse, and falls for his first girl. He basically becomes a typical American teenage boy—only Japanese.
Heading Home
But all of this rises to another climax when Manjiro decides its time for him to head home. The captain's at sea; Manjiro doesn't like his apprenticeship as a cooper; the girl he likes is someone he just doesn't think he can actually get. So why stay? Why not head home? The only trouble is, he's lived in America for so long at this point that returning home definitely won't be easy either… nor will he be the same once he gets back to Japan.
Falling Action
Delays, Delays, Delays…
Okay, this section is all about delay. Manjiro's made his choice to go home, but home is still a long way—both in distance and in time—away. He gets on a whaling ship but doesn't quite make it to Japan; goes back to Connecticut briefly; heads to California to pan for gold; finds said gold; and funds his and his friends' trip back to Japan.
But once he's finally in Japan, Manjiro's thrown in jail because people think he's a spy. See what we mean? Resolution: It's so close, and yet so far away.
Resolution
Dreams Come True?
There are kind of two endings to the book. The first one is the actual resolution, but, well, it doesn't totally resolve things. Instead, a guy comes for Manjiro on the order of the daimyo. He doesn't know why, though, and so the story proper ends with Manjiro uncertain about whether he's about to be sent back to jail or honored by being recognizes as a samurai. Manjiro remains calm, though, which lets us know that no matter what happens, he's going to be okay with it.
Then, in the Epilogue, we get the true resolution for Manjiro, which is that—yep—he becomes a samurai. It's a pretty landmark decision for the daimyo, considering Manjiro's the first Japanese to ever go from poor fisherman to super-high-class samurai. It takes a long time, but Manjiro majorly makes it.