I posted a pic of Yuko a long time ago in this post, but have decided that since I still love this manga, I'll post some more pics of her :-)
In this pic, you can see the level of detail that the creators - a group of women named Clamp - put into almost all of their drawings. This is awesome on the one hand, but often makes my head hurt trying to look at everything, lol!
In this pic, you can see Yuko's personality. She's a bit mischievous, a bit perverse, something of a bitch, but always good at heart :-D
And, of course, she's usually sexy as hell, lol!