Around the eighth and ninth century in Japan, soldiers slowly became known as samurais. Contrary to popular belief, samurai was a class of highly-respected people, not just fighters. Thus, girls and women were samurais, too, and learned sword fighting and martial arts, not to the level of men, to defend their homes and their lord.
Japan isolated itself from foreigners until Commander Matthew Perry from the United States sailed to Japan on his mighty “black” steamship on July 8, 1853. By demonstrating his strength by destroying buildings with his great cannons and sailing without the help of wind, he forced Japan to open its doors to foreign trade.
Some samurais, who wanted to keep the foreigners out, clashed with those who supported the Emperor and the Shogun (the head of the military), but eventually lost. After seeing how modern other countries were, the Emperor equalized the classes, abolished the samurai class, and forced the painful process of samurai warriors cutting off their hair and giving up the right to bear swords.
Aritomo, in the book Accidental Samurai Spy, was caught in the time when traditionally-thinking samurais wanted to maintain the way things had been for hundreds of years. Living with his enemies introduced him to a new of thinking.
Even though no samurais exist any more, they are still revered by the Japanese as powerful, brave, disciplined, and honest warriors.