Small Japanese ink pot?

This little pot is about 3.5" high x 3" diameter. It has both a label in Japanese on the top and a "Made in Japan" label on the bottom. It is red clay with white spots, a random green stripe and clear glaze. The interior is also glazed. The finish is very smooth and shiny but the glaze is so clear that it looks like a rough finish. I feel like it has a purpose, but not certain what it could be. Too small for a vase and probably made for export due to the "Made in Japan" label. Does anyone have a thought as to what it is for? I thought it might be an ink pot for calligraphy... Such a pretty, lumpy little thing, that I couldn't pass it by. A fair amount of effort went into making it.