Fascinating.

Over on the right, isn't that tokisaki_kurumi?
She's got the clock-pupil and everything.
(Of course, I could just be seeing things...)

Are these all really original characters? I could swear I have seen some of them before.

cokerpilot said:

Are these all really original characters? I could swear I have seen some of them before.

I see both Tokisaki Kurumi and Eucliwood Hellscythe

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.

Valentine322 said:

I think the one in the bath, the red-haired with ahoge is Rias Gremory.

That'd be my first guess as well, as that was my first impression of who the character is.

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.

The one with Hellscythe seems to be a character from Assassin's Pride (same hairstyle and all), but I don't know enough about her to make a tag.

Ah~, that's merida angel, then.

Edit: Given I'm pretty sure at least some of these outfits are non-canon, should this have alternate costume, as well?