Note for the unaware, the above is not pronounced in the same way as Santa Claus' catchphrase but is instead the stereotypical OujoSama laugh (short o, not long).
Typically a young(?) women of good-breeding (or the stubborn belief that she is) with a high opinion of who she is and how people should treat her.
I have been told that one of the best examples comes from the first in the Sakura Wars games, but I don't know her name.