Please, help to identify Japanese porcelain dragonware mark
We have a Japanese dragonware tea set for ages. My grandma bought it in antique store in Europe in late 1940-s.
It marked in Japanese, and we cannot identify the seal using renown sites as Gotesborg.com. We visited many web sites, but nobody could help us.
The tea set is very beautiful, in orange-golden-blue tones with the accents of white and brown. It consists of 4 cups, 8 plates, teapot and sugar (candy? ginger?) bowl. There are no Geisha images on the bottoms of the cups.
Attached please see photo of the seal.