Vampirism is the dominate trait. If a pureblood and human were to have children, their children would be noble class.
[Blushing a little]
I-I'm only considered a princess because I'm a pureblood. The pureblood are really rare. Since the pureblood have the ability to exercise control over other vampires and humans, the other classes reverie and fear us.
[On the flip side it makes them the ultimate prey, but she doesn't have to go into every detail.]
Kaname was the ruling king most recently, after the passing of the senate, but... [She shakes her head. He abandoned that post.] At home right now, I think there are individuals who would like to claim that title.