History
  Not much is known about Nasuti, or her past. Why? Because the show is called 'Yoroiden Samurai Troopers', and she's merely a member of the supporting cast. A very important member yes, but still no main character. What is known is that she's the product of a Japanese father and French mother, and is seemedly an only child. A wealthy only child at that. And where she get all this money, and this big fancy house, you ask? She stated in Gaiden that her grandfather left it to her after his death by the hand of Rajura.
   Like the Troopers, the Yagyu family lineage stretches far back into Japan's history. During the age of Tokugawa, the Yagyu samurai were the master samurai of the shoguns. Their wealth still exists to this day, which is shown by the size of their house it's close proximity to Tokyo.
  Before the Dynasty war, Nasuti lived in France, presumably with her parents. She returned to Japan when she was 17, and got a job working with her grandfather, a Professor at Shingoku University, who taught 'Study of Legend'.
   When the first battle for the fate of the Earth broke out, Nasuti was right there in the thick of it. When it was discovered that she and Jun were the only two left (save for the Troopers) free from the Dynasty, they were teamed up with the heros.
   Here's where the whining happens. 'Nasuti and Jun just got in the way, the Troopers could have won without them'. Yeah right. Maybe, just ~maybe~ they could have done it without Jun (he was a pest, yes, but he was occasionally helpful), but without Nasuti, they were pretty much screwed. How quickly we all forget the time that Arago seperates the five and Nasuti, the only one who knew the poem of the yoroi, was charged with finding and reuiniting them. And did we all forget the bickering between the five during their first battle? Nasuti was a big help in stopping those squables, and she helped them to learn more about their armor, and to better understand it.
   Also, Nasuti provided the Troopers with food (a major feat with Shuu around), shelter (quite nice shelter I might add) and both moral and intellectual support. Remember, the soldiers on the front line are important, but the people supporting them are equally so.
   The war, like all wars have a tendency to do, ends. Jun's parents are gone for good, Nasuti's lost her grandfather, and the five Troopers are suddenly warriors no more. So what happens? They all move in with Nasuti! Yay! Which of course is good for everyone. Most of the time at least.Of course there are a few arguments, and occasional hurt feelings. But things are good. Of course I'm sure Nasuti isnt thrilled all the time (if any of you have brothers, you can sympathize) by having so many men in the house. First off, I'm sure any hidden sweets are found and devoured by Shuu, and most likely all possible suitors for our girl are ran off, either intentionally or no, by the guys.
   And that basically sums up the known information on Ms. Yagyu. Love her or hate her, you have to admit she's at least somewhat important. And, in my opinion, one of the best girls in anime.