I've got a fair few problems with this one, to be totally honest. Were it not for these, I'd actually be all sorts of fine with Kaori.

> British but with a Japanese name. No explanation.
> Also no explaining how she got to Japan in the first place.
> Tragic backstories rife with rape and torture are criminally cliche.
> I can see the first ten years of Kaori's life being happy, but that ten-year mark for her also coincides with the start of WW2. Not a very happy time, much less in England, which was I'm fairly certain was economically ravaged by the thing. With a bit of explaining, though, I can see Kaori being at least relatively happy during that time. (strangely, her kidnapping coincides with the end of the war)
> [s]Good at hand-to-hand [i]c[/i]ombat for no reason[/s] actually, you're a vampire. This one makes sense on that principle alone.
> This isn't Cirque du Freak. We don't do apprentices.

I can certainly see effort though, and that's a good starting point no matter what my issues with your character is :)