For December, it's Kukuru Anrakutei!
From the anime, she's the silent-type from the group. She's shown to be unlucky, hardly felt, emotionally unstable and gloomy.
But I find her real cute in her different outfits, especially the one where she has braided hair, twintail, cap+twintail and the other one with a star pin.. no wait, it would have been better if I enumerate everything she wore in the series.
Why I chose her? Because she has long black hair. And her casual outfits are cute. No, really, it's the hair.
By the way, if you noticed I changed the format of the categories to the right. It's just so anyone can easily look for the songs tagged either by anime name or by artist. I believe it also looks way better than having one collapse menu. The new one looks less clattered.
Oh, and pardon for the not-that-great photoshop skills and changing the plain font blog title.