How can I identify a pottery mark on Japanese porcelain?

Question

I have a set of beautifully decorated cups saucers and small plates with a jug and a teapot. It was bought by my father in Japan just after it surrendered in WW2. I have searched the net and cannot identify the marks on the cups or plates. What sites are there that can help me without charging money.

Answer 1

If it is from Japan it should be stamped: Made in Japan.  Be careful, it may be radioactive if it is from WWII era.

Answer 2

On the left of this site is numerous companies that produced porcelain in Japan. I think it is one of the mose extensive that I have found. Good luck.