I dont know much about oriental ceramics, but i know a man who does Keith Jennings, he is on my forum, but i will add a link to here so he can take a look at this and other posts.
Hi, The dish is Japanese and because of the shape would be called 'nagazara'. The blue decoration appears to be printed, as does the mark. The mark looks like it is written in katagana, not sure what it says. Probably modern, circa 1950-now. Cheers, Keith