This is an Atsumi-style Sue ware short-necked jar that has been baked so well that you can hear a high-pitched sound when you touch it with your finger.
A thin rim can be seen on the rise of the cylinder, and the body has been scratched with a comb.
It has an ash cover and a natural glaze, and I think it can be placed on the front side.
I put water in it for an hour and it didn't leak.
