A Kogaratsu sake cup fired in the early Edo period. It has a weight peculiar to Kogaratsu, fits in hands, and the deep shape shows the rich landscape.

The iron glazed design on the rim is called “Kawakujira (skin of whale)” because the glaze colour’s contrast resembled the whale’s epidermis and the fat layer under it. The iron glaze was supposed to reinforce the rim, but it is inferred that the tea masters began to call it to associate with the whaling culture of Karatsu port. The black border distinguishes the inside from the outside, resembling the tea room itself, which is separated from everyday life.

There are no notable defects other than a single hairline. Most of the Kawakujira types were excavated pieces, so such good condition like this is rare.