I'd find it really damn interesting to know about the pre-Tokugawa Shogunate era. Everything after that I more or less know about or can find out.

Japanese History
 

Yeah the Tokugawa era is awsome and reading about the time of Oda Nobunaga is good to though you're right excessum there should be

The question is, how do we know what would be factual and what would be speculitive?<--sp? Japanese history is actually very bloody. For the people in here that know about the japanese invasion of China and Korea, know how brutal they can be. Samurai and Ronins and Ninjas are all cool and stuff, but what about the non cartoon stuff. I think this would actually shock a lot of you. Just my 2 yen.

I'm only curious can cousins marry in Japan?

To be honest, there were some problems with the royal family here a couple decades ago because they tried to keep the royal blood all in the family. There were marriges between relitives and some complications happend. I think it is still ok here.