Shamps is, frankly, jumping to some pretty stupid conclusions in this
one. There are quite a few simple reasons for Ranma to be nice to
Kasumi: she's his main source of food, she probably couldn't stand up to
the kind of good-natured ribbing he gives Akane, Soun would murdalize
him if he *wasn't* nice to her. Take your pick.
This could lead to some hilarious comedy if you want to play it that
way. I can imagine Ranma coming to the conclusion that Shampoo is under
a spell and trying various ideas to cure her, and her misinterpreting
his actions. But as a serious story, I'm really not sure how much
farther you can take this before it becomes obvious to Shamps that this
current plan is a dumb one.
Gary Kleppe
http://www.execpc.com/~kleppe/comics.html