I have no idea where she's from, but she's certainly very cute!
When a reader who prefers to remain anonymous sent this in, the only clue s/he has about this photo are the words "Blank Note" and "Himawari" which makes absolutely no sense to me. Anyone else have an idea?
Oh, you may have noticed I turned comment moderation on. I was spammed the other day so I may need to do this from now on. Don't worry! I'll be checking comments as often as I possibly can!
First seen on Winter Comiket 2009! Thanks again for everyone's contributions!
EDIT: Thanks to anon for researching about this! The character is Aries from the Game and Manga, "Hi.Ma.Wa.Ri"!