This is an antique Japanese military sake cup, decorated with a pair of flags that are embedded in a double-walled glass sake cup. These are little physical flags that have been place inside - seems to be that the cup was made first but with the bottom open, then after the flags were placed in there (they do not move inside the cup) it is then sealed with the bottom. The bottom words are about how they have monopoly on the sale of this design.

Condition: Mint

Size: 2" across