SUMIDA YAKI aka SUMIDA GAWA WARE (隅田焼)

Sumida Yaki is famous for its bright, humorous and sometimes odd motifs. It is called Sumida Gawa Yaki by many because the workshops were by the Sumida River in Tokyo. In Japanese it is just called Sumida Yaki. I recommend the book  “Sumida—-according to us” by Herbert Karp and Gardner Pond, for more in depth information on Sumida Yaki. They include the the issue of those that mimic Sumida, sometimes erroneously called Poo ware by some antique dealers (pg 17). 

Probably the most prolific and famous potter in Inoue Ryousai. He worked closely with other noted artists including Ishiguro Koko.

This mark is that of Ishiguro Koko (石黒香香) who used bone script 香二 for his mark. The 二 is the iteration mark used in old Chinese (for repeating a character). Ishiguro Koko's name is written three ways that I know of.

(石黒) 香香 , (石黒) 香二, (石黒)香々

Hara Gozan

Inoue Ryosai