A was originally a square wooden box used to measure rice in Japan during the feudal period. In 1885 Japan signed the Convention du Mètre and in 1886 converted all of its traditional measures to the metric system.
Masu existed in many sizes, typically covering the range from one , one , isshà Âmasu c. 1.8 L) to one .
The advent of modern rice cookers and a higher calorie diet in Japan has made them impractical for measuring portions of rice, though the plastic cups used with rice cookers now have a 180 mL or one gà  capacity
Today masu are largely used for drinking sake. Drinking vessels are made from hinoki (Japanese Cypress wood), as it imparts a special scent and flavor. The drinker sips from the corner of the box, which pours it into the mouth.<br>Toasts are poured by stacking a pyramid of the guests' masu on a towel or cloth, with the toastmaker's masu on top. It is then overflowed until it fills all the masu beneath it. This symbolizes the generosity of the toaster to their friends and how they wish to share their happiness and good fortune with them.
A small , lidded form of masu, is sold for serving pepper, salt, sugar, and other dry condiments at the table.