Do the specials of the manga Zetsuen no Tempest continue the story after the end of the manga? Are Yoshino and Hakaze going to end up together?
The end of chapter 6 of the extra story shows that Yoshino starts to open up to Hakaze while he was walking her home after her job (Mahiro suggested him to do so).

On their way, he says to Hakaze, if she has a boyfriend one day she should introduce him to Yoshino and he'll be happy for her from the bottom of his heart. But Hakaze replies that those things don't make her feel better at all. 

Then Yoshino suggests holding hands as its dark and late and she might get lost. Hakaze refuses and says that it only applies to kids. Yoshino tells her that he can't walk as confident as Mahiro, but if there is a one in a million chance that he could get lost, he wants to hold her hand. Then both of them intertwine their fingers and walk together.

Thus, I think it's indicated that they will end up together.