This is a type of Japanese pottery most identifiable for its humble forms and use of translucent white glaze.
It originated in 1604, when Japanese samurai lord Terumoto Mori funded the Lee brothers from Korea to make ceramic ware in his castle to provide the utensils necessary for tea ceremony, which he was very interested in. The original Hagi ware resembled famous Korean white ware bowls. However, the style has changed to reflect Japanese aesthetic taste over the years.
The most standard finish for Hagi ware is in a soft light color. Potters mix local clay that is not refined, and as a result, many small cracks may appear in the ware after being fired. The piece is then decorated with translucent glaze, which gives it a wet appearance. The difference in temperature between the clay and gaze tends to create many tiny spider lines on its surface. Some may think this is a defect, but this look is what Hagi ware is famous for. Water may drip a little bit from a brand new teacup, but with a continuous use, tealeaves will eventually stop the leakage. Regular use also adds a natural color of tealeaves to the ware, and the teacup begins maturing and revealing its own unique color. This is called the “Seven transformations of Hagi”.
It may sound inconvenient to own a teacup that may leak when you first use it. However, with a bit of patience, you can witness your Hagi teacup transforming like a living being, as if you were watching a child maturing with time. It is understandable that tea practitioners love Hagi ware, which resonates with the wisdom of tea ceremony; Love can grow with tender, loving care and patience (Conquering leaks-obstacles, one might add).
By the way, for folks who don’t want to wait until potential leaks are completely gone, leave the new ware in a mixture of thin rice gruel and water for a half-day or so, wash it out, and dry it. Repeat the same process a few times, and you should be able to use it normally after that.