My wife helped me pick out Yoko's surname! It's all super poetic: It means "An Anchor made of Storms." More literally. And when written differently just means ANGER! So, it was the perfect choice for Yoko and the type of person that she is.
Oh yeah. Her Principal is an asshole too that doesn't listen to his students. NOT THAT WE'VE EVER SEEN A PRINCIPAL LIKE THAT BEFORE!! Cliche? Well yeah, but it's so fucking common in reality. And did you notice that the other students refer to Cassandra by her first name and a nickname instead of her last name? That's because they all like to pretend like they are close to her to make fun of her, since in Japan your first name is usually reserved for people who are close to you.
Soooo, why does Cassandra call Yoko... Yoko?
CHEERS!