Hi, I also cannot give you a better translation of the calligraphy on the inside than KC...
However it is likely some poem or a good wish! Your sake cup is Kutani porcelain, and I think the mark says "Kutani Kinko do". It could be from the 1930s (I tent to this date) or a bit later (1950s?). The technique of micro-calligraphy is called "Saiji", here is a link to a kiln that still uses this technique and has some information on it:
http://saijitamura.main.jp/what%E2%80%99s-saiji . However, the technique described on that site is the more difficult one, whith the writing done by a brush. Your calligraphy looks like it was done by a pen, which is more easy.
Mat
