Japanese periwinkle bowl-cum-planter

This planter is a bit over 4" high x a bit under 5.5" in diameter. It is not signed but is hand painted. It is decorated on two sides, so broadly that the design almost goes around the whole pot. There is also some decoration on the rim.

Pretty sure it is Japanese, but not certain that it started its life as a planter. The hole in the bottom appears to have been roughly drilled sometime after it was glazed and fired, not made when the clay was soft. The interior glazing appears to have been unevenly eroded away. There is a widely varying border between the remaining glaze and the ceramic. I do not think that it started its life as a planter. The interior was coated in black dirt when I found it.

This pot was at the local GW for several weeks, maybe two months, or so. I was interested in it when I first saw it, but it was too expensive, I thought. Finally, the price went down and I could not find anything else interesting that day, so decided to get it. I have no idea what its original use was intended to be.