RyuZU

Race: Automata

As described by Naoto, RyuZU has soft and smooth silver hair, snow white skin, golden eyes, and lithe arms and legs. She wears a simple, elegant black and purple dress, and a hair ornament made from white gears and a cloth with red, green and black color. She also has two black scythes made from gears hidden in her back.
While in her special mode, her clothes turns into a tight-fitting crystal-colored wedding veil and her golden eyes change into a blazing ruby.

Like her code name (Yourslave) implies, she is an automata made to serve her master - in this case, Naoto.
Since she does not have an offensive language filter installed within her, she tends to be very rude to others, although she is oblivious to this.
Unlike most automata, she possesses her own free will, and genuinely wants to stay by her master's side.

(Source: Clockwork Planet Wiki)