Not very accurate. The movie exaggerated some parts. For example, the samurai's unwavering loyalty as shown was a bit overdone. In real life, there were internal conflicts among samurai too.
Perhaps she could be a relative of Tenten. Since Tenten has an affinity for weapons and has some samurai - like qualities in her fighting style. A Samurai Girl related to her could have been trained in the ways of the samurai in a more traditional sense. She could enter the story when Naruto is exploring a new area near Konoha and they meet by chance, and then a whole new adventure begins.
Yes, 'Black Samurai' is based on a true story. It tells the remarkable tale of an individual who overcame many obstacles and challenges in a particular historical context.
Samurai novels often focus on the code of honor of the samurai, like bushido. They usually feature samurai characters with their swords, duels, and loyalty to their lords. The setting is mostly in feudal Japan.
A samurai named Takeshi had a difficult choice to make. His family was in debt to a powerful merchant, and the merchant demanded that Takeshi work for him to pay off the debt. But Takeshi's honor as a samurai was at stake. He couldn't bear to work for a merchant instead of serving a noble. So, he decided to enter a tournament. If he won, he would get enough gold to pay off the debt. He trained hard and in the end, he won the tournament, saving his family's honor and paying off the debt.
Another great samurai story is about Tomoe Gozen. She was a female samurai. Tomoe was known for her incredible fighting skills and her participation in battles. Her story breaks the stereotype that all samurai were men and shows the diverse roles that women could play in the samurai society.
No, it's not a true story. It's likely fictionalized or based on some historical elements but with creative liberties taken for entertainment purposes.