There have been many legends & myths concerning the origin of Sumida Ware. One of the more colorful was that it was made by a colony of Korean dwarfs. Another was that it was made by Koreans that had been captured by the Japanese and relocated to the island. Although entertaining, neither of these widely spread rumors are true.
Sumida Ware was made by Japanese potters for export to the western world. The earliest known pieces of Sumida were made in the beginning of the 1870's. This ceased in 1941 at the beginning of World War II, although there are two different styles that were made in the 1950's.
The majority of this pottery has a distinctive look. The rim drips with a high gloss glaze over an unglazed body. The glaze usually coats the interior. Figures in high relief are attached as decoration. These figures can be people, animals or flora. The unglazed body is usually in tones of red, green, black or orange. These items were either for decorative or functional purposes. Vases, bowls, cups and teapots are the most common pieces.
Most of Sumida is signed with a potter's mark. The lack of one does not impact the collectability of the piece. The signatures are usually written within a white clay seal, often referred to as a cartouche but they can also be impressed into the piece. The three major studios represented by these signatures are Hara Gozan, Ishiguro Koko and Inoue Ryosai. Several generations of potters worked in the studios.
The value for Sumida can range from a hundred to thousands, depending on the complexity and size of the piece. Some of the considerations is the overall look and balance of the pottery plus the color appeal of the glaze. The number of figures or complexity of the scene is a factor. As with all things, the condition makes a big difference. Pieces of this pottery are in collections of museums.
A very informative book to read is "Sumida...According to Us" by Karp & Pond.