This is a very rare antique Japanese military sake cup, decorated with a big naval insignia in the center. The words on the back of the cup are "Aircraft Carrier Akagi 13th Draft Association" and the name Kawaguchi. The carrier Akagi needs no introduction - launched in 1925 after a conversion from being a battlecruiser, and served as the backbone (and flagship of the Kido Butai) of the Japanese carrier force up until her sinking at Midway. Getting any kind of cup attached to one of the full carriers is extraordinarily rare. I'm not 100% sure what "13 draft class" here refers to - quite possibly it's Showa 13th, which means 1938, although there's no way to know for sure how they counted.

Condition: Excellent - one fairly minor spot of damage on the paint at 3 o'clock, please see closeup

Size: 4.25" across