This is an antique Japanese military sake cup, decorated with a cherry blossom in the center. The words on the back are "Gift to Army Artillery Major Haraguchi Shutaro" and "18th Field Artillery Regiment Officer Corps". It's quite rare to have a cup with a named major (or really, any rank above lieutenant). 

Condition: There's a very small chip of the paint at 4 o'clock, please see closeup

Size: 3.25" across