In "ARSA continuous story", a man called the Dreamweaver lets people in to a special room where they change according to conscious or subconscious desires. Mostly it makes them younger, since the story was posted on the AR archive.
However, in part 13 Jennifer instead wishes to become more beautiful. She's pleased at first, but soon it becomes apparent that she's received more beauty than she can handle...
http://old.ararchive.com/modules.php?name=Search (search for "continuous story" and the chapters should pop up.)