Noun: "(chiefly Japanese fiction) a calm, aloof, reserved fictional character (usually a girl) who has a hidden soft side, especially for a romantic interest"
As an otaku who prided himself on having wide and generous interests, I was all for kuuderes and tsunderes and whatever, but there was definitely a lot to be said for a bright, earnest smile like that.
True, she wasn't very expressive—or anyway, I didn't feel like I saw a lot of emotion from her—but if I thought of her as a kuudere, or one of those “weird girl” types, that could actually be seen as a positive.
The cool and tough exterior she displays makes for a good kuudere, and the blue eyes and silver hair already sets her up for the role in the Clannad series.