Kira Vincent-Davis is an American voice actress, noted for her roles in English-language dubs of anime series. She is likely best known as Osaka in the comedy anime Azumanga Daioh, Ruri Hoshino in Martian Successor Nadesico, Quon in RahXephon, Nakahito Kagura in Steel Angel Kurumi, Lucy and Nyu in the dark drama/horror anime Elfen Lied and Elenore Baker in Madlax. She starred as Misaki, the main character, in Divergence Eve. As you can see, she has a wide vocal range.
She has worked under a number of different names, including "Kira", "Kira Solar", and "Kira Vincent(e)".
Whether she can kill people by writing in a notebook remains to be seen.