Futaki Kanata

Kanata is Haruka's twin sister, though this is only revealed later. She acts extremely cold to Haruka, although it is later revealed she is forced to treat Haruka coldly by her kinsmen, and actually made efforts to release Haruka from them. Since the only real difference between Haruka and Kanata is their eye color, Kanata uses this to her advantage when she impersonates her sister with colored contacts. Kanata cooks well, while Haruka is very specialized and not as good, and this is one of the few ways to identify her when she is impersonating Haruka.

In short words, she has the polar opposite personality to Haruka the twin sister.