A cruel and selfish black-haired girl who says she understands and respects bullying but resents being called a bully herself, Yozora's difficult personality drives away anyone who might wish to make friends with her before she meets Kodaka. She is physically abusive towards, and often argues with, Sena and manipulative towards Maria, who she cons into giving up an empty room for the use of the Neighbor's Club, and Yukimura, who she fools into working for the club as a crossdressing cosplay maid. The only person she can't insult is Rika, as Rika takes whatever insult she gives her and deflects it back with a dirty joke that leaves her tired - to the point where she just does what Rika says (like crossdress for example) rather than argue.
She is Kodaka's childhood friend, though at the time, he believed that she was a boy, calling her "Sora"; her nickname for him was "Taka." On the day that Kodaka moved, she intended to wear a skirt and reveal her gender to him but was too embarrassed to do so. She seems to have feelings for Kodaka.
It is implied through out the novel but is finally revealed in volume 7 that the only reason Yozora made the club was to spend time alone with Kodaka; and that she had no interest in gaining friends in the first place
Despite the fact that Yozora is a main character, not much is known about her background. Other than her childhood with Kodaka, almost nothing known about her home situation, family and other things involving her background unlike Kodaka and Sena, where you know much more about.