This is an antique Japanese military sake cup, decorated with a helmet, a katana, and a flag. The words are "China Incident Commemoration'. There's also the words in gold "Hachiman" which is the name of the god of war - probably a prayer of thanks for returning. The exterior of the cup is an interesting green colored glaze embossed with cherry blossoms and a poem. 

Condition: Mint

Size: 2" across