Barring red herrings, the other two human characters are clearly the human selves of Black Gold Saw and Chariot (the new blond character), but then who is she? Black Matagi?

...oh wait, they both have armbands.

wut? But Arata looks nothing like Saw. All the others are really pretty much just older versions of the Humans. Same body types and hairstyles and such. Arata has these cute little thick eyebrows while Saw, well, don't.

I'm only basing it off the red eyes. And that they were put up on the website at the same time. We'll find out one way or another. Hopefully.

For now I'm assuming she's Saw. Or teacher lady. Er... Black Gold Teacher Lady?

Fairly certain that Saya is BGS. Granted Saya only has short hair but the bangs give it away.