From what little I understand of the commentary, these are characters from light novels. So no, not original. Now the problem is with identifying them.
I think the one in the bath, the red-haired with ahoge is Rias Gremory.
The middle-bottom character has a little animal companion which, I think, is the little dragon-creature from SAO. I don't know her or its name, but maybe this hint will help someone.