The relationship between samurai and ninja in feudal Japan, Essay Topic Help (IB)

Okay, so:

Currently, my selected topic is the relationship between samurai and ninja in feudal Japan. This encompasses a large time frame, about 600-800 years depending on where you place your cut off date. It just hit me that this is rather broad. Should I try and narrow down my topic? And if so, to what? Thanks for your help

This is a good one. I read that the ninja were taught by the warrior monks. I also read that they were clans of peasants rebelling against the authority of the samurai class. I also read that they were assassins for hire. Over the centuries, ninja have been many things, I think! Two famous clans are Togakure and Koga.

I think if you research historical records of ninja, you'll come to certain prominent clans. You will narrow your thesis by discussing one or two particular ninja clans and their contemporaries. That's my prediction. So, do your research, and narrow the scope of your paper to the level of the clans you cover.

Be sure to give the paper an overarching theme!