This may be a shot in the dark ... but I think that's Japanese. Shibata porcelain (made in Shibata Japan, obviously lol), has a similar symbol like the one in the lower right corner there. Shibata's stamp actually reads "Shiba ta To-ki". A lot of Shibata porcelain is newer, late 90's stuff, made for souvenirs and the like. It can be quite beautiful however. So what I'm wondering is if your frame was made in Shibata
But I could be way off, it's just a comparison guess.
