Hmm, there's not really an IRL inspiration for Yui. I do think people like her do exist, though. Maybe not as pronounced, but then again, she is a fictional character that I made up. :P
Heh, thanks a lot. I do agree with that assessment, as it is how I view CH, too. The visuals are a tool to enhance the story I want to tell and the adult parts are the cherry on top because adult content is like spices to a good dish - it enhances what is already there and shouldn't be the whole base of a dish. :)