Sakaki is a tall, athletic, and curvaceous high school student who is quiet and shy, although because of her appearance most people take it for reticence and think of her as a "lone wolf." In truth, Sakaki is obsessed with cute things-- especially kittens. When the super-cute Chiyo Mihama joins her class, it makes Sakaki even more self-conscious, although she eventually comes to be a regular part of the Azumanga Daioh group.
When another athletic student, Kagura, joins Sakaki class, she originally tries to pal up with Sakaki. Unfortunately, the two aren't very compatible: Sakaki is always daydreaming about cute things, and Kagura is much more like a stereotypical jock-- not too bright and more interested in the "cool" than the "cute."
Sakaki is the character's last name; her first name is never revealed, as all the other characters in the series refer to her by her last name (often with the honorific -san attached).
Sakaki's cool aloofness is very attractive to many of the other characters, particularly Kaorin.