Olivier Mira Armstrong

Olivier Mira Armstrong is the Commander charged with Tenrai, and a close personal ally of King Callum. She is Alex's older sister.

Callum -
She is a close personal ally of Callum, having been his superior when he first joined the Military.

In the Final Arc of Callum's story, it is revealed he's been madly in love with Olivier ever since they met. She scoffs it off. She never recipicated the feelings, however, it's implied she found them 'sweet'.