Traditionally, sake is served in wooden box cups known as masu with a standard measurement of  180 ml or 6 fl oz.  These tiny cedar  box cups were thought to complement the taste of sake. Tradition requires the masu be filled to the rim as a sign of prosperity.  Nowadays, sake is more typically served in ceramic cups. The cups used for drinking sake tiny vessels called ochoko.  While not a traditional serving glass a shot glass is also sometimes used.
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