Japanese ceramic mug - GOSUDHARMA ROKUHEI SUSHI

A yunomi (Japanese: 湯のみ) is a form of teacup, usually made of ceramic material, taller than it is wide, with a cut or turned foot. Unlike the more formal chawan tea bowl used in the Japanese tea ceremony, the yunomi is made for daily (or informal) tea drinking.
There are special pairs of yunomi called meoto yunomi (meoto means "married couple"). The Meoto yunomi usually consists of two cups with the same design (sometimes different colors) but different sizes and often slightly different shapes (the larger cup being the "husband" and the smaller being the "wife").
Many contemporary potters, both in the East and the West, make yunomi and as a genre, yunomi has become a highly collected item.