For voice, try to aim for the dub/sub voice (link below), but your own interpretation is fine too! I'll also be accepting "Teen" voices for her too!
https://www.youtube.com/watch?v=jPX-YgCIGaE&feature=youtu.be

Please be prepared for whatever comes as this character goes through a transition in the series.
For a quick background, Kisara is a college girl who's trained with a sword from a young age and comes from a big family. She and Rentaro are childhood friends, but she still treats him like crap, for the most part. Her parents died when she was young and thus, will be a large factor as to how she develops later in the series.
So.....have fun with that.

(I would have liked to included a crucial line for later in the series, but I'd hate to spoil things for new fans. So, be ready for a dark turn....as if I hadn't already said that a dozen times...)