Need Help with an Imari Cup and Saucer

I bought this cup and saucer at least 2 summers ago, meaning to research it then, but forgot about it until now. The lady they were selling for inventoried all of her things with the price she paid. This cup had a note that said "signed, $100" and her inventory number. What is so special about this cup and saucer that she would pay a hundy for it?
It is marked on the bottom but I don't know the mark.

It measures: Saucer 5 1/4" diameter; Cup 2" high x 3 1/2" diameter. Thanks for any help.

 

Wonder if she thought it was an English Derby Imari cup and saucer.

https://www.google.com/search?q=derby porcelain marks&tbm=isch&tbo=u&source=univ&sa=X&ei=3nPIVNWpOoubNrD2gZAM&ved=0CCYQsAQ&biw=1687&bih=1033&dpr=0.85

Mark doesn't match, and might be an imitation.

I don't think it is Japanese.

Pictures of English Imari
https://www.google.com/search?q=Eng...Bg&ved=0CAgQ_AUoAQ&biw=1687&bih=1033&dpr=0.85

 

Clutteredcloset49 is right, this is certainly is not Japanese and goes into the direction of English Imari. I also think it is an imitation, though...
Mat