This cup is Hasani-yaki potery.
And the back side is --
Can you see the line?
This cup was broken at the big earthquake and the master repaired with KINTSUGI.
KINTSUGI is --- according to Wikipedia
is the Japanese art of repairing broken pottery with lacquer dusted or mixed with powdered gold, silver, or platinum, a method similar to the maki-e technique. As a philosophy, it treats breakage and repair as part of the history of an object, rather than something to disguise.
Looks KOFUU ---doesn't it?
KOFUU means ancient and modesty.