Kuya Amururineuruka

Kuya is the young ruler of Kunnekamun. She befriends Hakuoro after having many secret meetings with him, which were led to by her curiosity of the almost supernatural feats that Hakuoro was able to execute. She pilots a silver Avu-Kamuu, although she is not used to war (which later wreaks havoc on her mind). Kuya cares for the welfare of her people, but doesn't know what decision to make. This proved to be her downfall, as it ultimately leads to a global war.

Later in the series, she suffers a psychotic break after witnessing Genjimaru's death and Hakuoro's true form, and reverts to the mentality of a young child. (Source: Wikipedia) She apparently suffers from a complex about her gender, as she believes that her people (or more likely, her royal court) aren't able to see her as a respectable ruler, on account of her being a woman, so she often wears a mask that conceals her entire head. After her mental break, the only person she still recognizes is Hakuoro.