Verified answer

Why do they feature it: Because some people get off on that. Pedophilia is just one member of a long list of strange sexual deviance's that some people have, and the majority of people have at least one.

Isn't that illegal? Depends where you are and what your local laws say. In Japan you can pretty much claim that any character in a work of fiction is over the age of 18 by stating it in said work of fiction, even when common sense would dictate otherwise. You only have to walk into an eroge shop (seriously, try it if your ever in Japan) and look at the back of some of the boxes to see what a loose level of enforcement the Japanese have against non-photographic depictions of child pornography.

I mean, does she look 18 to you:

http://www.renderat.com/renders/noumi_kudryavka_ii...

Didn't think so, me neither (she's actually 14 if your wondering), but since the game she's from says quite specifically 'all characters herein are over the age of 18' she can be depicted having as much sex as they want no problem. Now, in the case of characters from a different franchise with pre-established ages, you would thing so right? again, nope. The artist only has to declare that they were drawn with the intent of them being depicted as over 18 (even if they look the exact same as the original) and its A-OK legally.

Different countries, different laws. In the UK you would be locked up and put on the sex offenders registry for possession of such images, Australia it would depend on what state you were in, US has laws in place to protect the right to artistic expression, regardless of how distasteful the art may be.