I wonder if MS would allow the release of some animu hentai games with real actual nudity. Probably not.
well...
http://zepy.momotato.com/2009/08/16/indy-galge-stopped-from-distribution-on-xbox-live/
But look at that screenshot. It's pedophilia loli-rape.
I'm pretty sensitive to the endangerment of children, and the sexual exploitation of them, but one pic out of context doesn't make it what you're describing. Within the context of Japanese culture, there's nothing remotely weird about it, but as a westerner I agree with all three gripes listed on that page by MS.
The linked page makes a big deal about censorship from MS, but dollars to donuts this wasn't shown to MS EU or PEGI when it was submitted for release; this is more likely about liability and the publisher respecting their contractual agreements.
Edit/Add: I re-read the linked article; it mentions indie-games, and a later commenter posts a snippet from the XNA guidelines, saying that games need to be OK for the whole world, every region where XBL is offered. So basically XNA is at the very center of the venn diagram where all this overlaps. I know it's hard to draw attention to indie titles on PC, but it's got to be easier than jumping through all those hoops.
What does uguu mean anyway?
It's the noise your ex- made when you turned her down, while she deliberated on whether or not to kidnap your rabbit.