She is  also something of a techno-geek who is never without her laptop computer and cell phone. She is not much of a student, and she tends to stay away from the cram school on days when test results are posted because she knows she won’t have much of a showing.

Chiaki befriends Mayuko on the very first day of the cram school summer session, and is delighted that she is not only friends with the “the smartest girl at school” (namely Mayuko), but that the friendship is also is letting her get close to her all-consuming passion: UFOs, aliens, and the mysteries surrounding them. Chiaki is the only character who appears in the series who appears in the series who doesn’t seem to feel the aliens have become commonplace; they seem to feed her imagination just as strongly as the tales of “little green men” did for previous generations. The rides she enjoys in NieA’s homemade UFOs are definitely highpoints of her life—even if they do end in massive explosions. If any of NieA’s UFOs survived more than just a few moments after being switched on, Chiaki would pay outrageous amounts of money for them and possibly be seen traveling everywhere in them herself.

Early in the series, Chiaki is everything that Mayuko is not. Chiaki is unconcerned about the future while Mayuko is frets over every coming minute. Chiaki lets slights and setbacks roll off her like water off a duck’s back—when an apology has been made, that closes the matter for her--while Mayuko tends to worry constantly about how to make things better, if things can be made better, and in general just makes herself miserable. Chiaki is also gleeful indifferent toward what others might think of her UFO hobby and takes pride in being tuned into something that others don’t seem to be paying attention to, while Mayuko is always worrying about pleasing others and fitting in. Chiaki also sees the magic in NieA while Mayuko just sees her as an annoyance and a source of constant assault on the cocoon she keeps trying to construct to stifle herself.

While Chiaki might have any number of ulterior motives for wanting to be Mayuko’s friend—access to someone who might help improve her test scores, access to someone who lives close to aliens—it is clear that Chiaki wants nothing than to be Mayuko’s friend. Sadly, Mayuko feels intimidated by Chiaki’s self-confidence and comparative wealth and even fails to understand that Chiaki is just trying to be a good friend. While Mayuko seems to suspect that invites her on the group date just because there is an uneven number of girls to the boys who will be attending, it seems equally clear that Chiaki was primarily trying to help Mayuko get over her shyness.

Fortunately for Mayuko, she eventually takes on some of Chiaki’s personality traits and by the end of the series, she has started to take breathers every now and then. As the series come to an end, Chiaki’s friendship with Mayuko is more balanced than earlier on, with Mauko offering her some support when Chiaki is down over the way the mother-ship vanished and no one but her seem to care terribly much about it.