Of course, we cannot write essays for you on this site. What we can do is to help you think about what you might write.
One thing that you might want to write about is why feudalism arose in Japan. You would want to talk about how land was given to members of the royal family to support themselves. These lands were typically run by local lords, known as daimyo, who soon came to be important powers on their own.
You might then want to talk about the basic structure of Japanese feudalism, with the samurai being the knights who served their lords (the daimyo). At the top of the system was the shogun, who was not the same person as the emperor. The emperors were officially the rulers of the country, but they had no real power.
You might also want to talk about how Japan had a long period of wars between rival daimyo wanting to gain control of the country. These wars did not end until Tokugawas came to power in the early 1600s.