I found these funny official (sort of) comics. Unfortunately they've been translated into Chinese from the original Japanese, but still enjoyable imo. Nothing spoilerific, unless you consider Touka being funny spoilerific.
This is volume 2 (vol 1 isn't as good as the rest, imo)
Here's volume 3 (Eruruu and Touka's insecurity in their own sex appeal = WIN
):
Here's volume 4 (You just KNOW this was bound to happen sometime
):
I'll see about posting volumes 1, and 5-8 sometime later.
Man, I wish someone could translate these or the original Japanese versions.