Found your Mark and it is for UCAGCO, "Occupied Japan". All items with your particular mark were made for import into the US during 1945 - 1952.
UCAGCO actually means United China and Glass Company which was originally called the Abe Mayer Company (founded 1850 and strictly an import company) with the US offices located in New Orleans and New York. In the 30s the company started the official trademark "UCAGCO" - becoming a prominent distributor of dinnerware, glassware and Japanese china during the early 1950's. UCAGCO was sold to Sammons Enterprises in 1956.
For those that don't know....following the end of WW II while Japan was occupied by US Troops, (1945 - 1952), import items to the US from Japan had to be marked indicating they came from Occupied Japan (although required - many items slipped through and some said "Japan" "Made In Japan") "Occupied Japan" and "Made In Occupied Japan". were put on items such as toys, pottery, glassware, china, etc. Collectors search for these items, especially those with the Occupied Japan and Made in Occupied Japan marks.
Still working on what your item is! Maybe a fancy candy dish? What do you think D&b?