She was created by a scientist obsessed with perfection and when she was "born" with such a large defect as being mute, he didn't waste any time throwing her away. She was able to struggle her way out of the trash and walked around alley ways and explored the town looking for someone to help her, but since she couldn't speak (and didn't really understand anything at this point) she was just ignored, even attacked, until her battery lost all its power. A strange, anarchist UTAU picked her up and brought her to her home in the back of a doll maker's shop (a home along with a handful of other UTAU.) The UTAU's "dad", just called Doll Maker, fixed Amaya up (it was actually rather easy, the scientist just didn't want to bother) and allowed her to live there with them.
Soft spoken and shy to new people, coming off as kuudere at first to most. Once she gets to know you she's rather childish, but kind. Strangely obsessive over dolls.
Amaya's concept art.