I haven't seen that many episodes of this yet, but it seems to have quite a bit of potential. Any story that revolves around using little girls as assasins because they've been through horrible ordeals is bound to be cheery, right? Seriously, though, this anime does look like it will be very good so long as it stays at its current level. The opening and ending theme songs by The Delgados are both great and other music within the show is very good. The animation is excellent and the seiyuu seem to be good so far. This is definately a series to keep an eye out for.