Cool anime! ^.^
Ahem, brainwashed girls who do not have any relatives nor any place to be, are being prepared as professional assassins and given mechanical bodies by a so called non-profit welfare organization. They have lost every consciences and do not hesitate to kill at all. They spend their lives smeared with smoke, covered in gunpowder and blood.After they were being brainwashed, they can kill with an innocent face and without hesitation at all. They don't think through their deeds and don't feel any pity. they destroy themselves and refuse to grow.
But of course i think you knew all that..
Sad thing, i haven't finish watching all the shows,only epi 1-6...*cries*