This is an antique Japanese military sake cup, decorated with the imperial standard of the Crown Prince. The words on the cup are "Overseen by the Crown Prince (referred to here as "Eastern Palace", which was where he lived)" "Great Military Exercise Participation Commemoration". The words on the back are "Taisho 10th Year (1921) November" and "Warship Ikoma Propulsion Department". This is quite interesting, because the military exercise that took place in November of 1921 was an army exercise, not a naval one. However, it took place along the coastal areas of Kanagawa prefecture between Tokyo and Yokohama. I suspect the emperor must've boarded the ship to observe some of the movements over the four day exercise. There was no naval exercise that year. Notably, the Ikoma was destined for scrapping the next year in 1922 thanks to the Washington Naval Treaty.

Items involving imperial family members, especially the future Showa emperor, are highly valued by Japanese collectors. The banner here is the crown prince banner - there's an extra box around the imperial chrysanthemum. The emperor's standard has no box.

Condition: Mint

Size: 4.25" across