The feudal hierarchy of Japan is much different from that of the United States. They actually have a caste system that is set and that you are born into. Their caste was the nobles and royal family, then Samurai warriors, then artisians and lastly the merchants. The two largest groups of the population are the warriors and the farmers. Their caste is so much different from ours because in our caste you are able to move form class to class. If you make money you are able to purchase property and own land. If you want to be a farmer you can farm, if you want to fight you can join the army or marines, if you want to be lazy, you can be a bum. You can do what ever you want.
In Japan, it is much different. When you are in a caste, that is where you stay. If you are born into nobility, that is what you are for life. If you are born into farming, that is what you are stuck doing for the rest of your life. The farmers can"t go and fight in battles, just like the warriors can"t come back from the battles and buy some land and start farming. They all have an obligation to eachother. They are all expected to support one another. The farmers give a certain amount of their crops to the government which goes to the warriors and everyone else. Just like the warriors go to war and fight for the farmers who are producing crops for when the warriors come back. The only way one can change their caste that they are born into. They never actually change their caste, but they are adopted by their inlaws into that class that their spouse is in. You aren"t adopted by an upper class but a lower class. If a merchant wants to marry a farmer, the farmer will be adopted to the caste, not the merchant to the farmer. So there is a adoption of caste's but not really changing castes. .