A masu (枡?) was originally a square wooden box used to measure rice in Japan during the feudal period. Masu existed in many sizes, typically covering the range from one to (一斗枡 ittomasu, c. 18L) to five gō (五合枡 gogōmasu, c. 0.9L). One masu was supposedly enough rice to feed a person for one day.
Today masu are largely used for drinking sake, as the advent of modern rice cookers and a higher calorie diet in Japan has made them impractical for measuring portions of rice, and the standard size is one gō, or 0.18039L.
A small (2.5 in x 2.5 in x 2.25 in h), lidded form of masu, made of hinoki, is sold for serving pepper, salt, sugar, and other dry condiments at the table.
There is an origami object that is called a "Masu Box" that can be created from a perfectly square piece of paper using the following instructions:
|Step 01||Step 02||Step 03||Step 04||Step 05|
|Crease and Return||Fold tops to centre, this is called a blinz fold after a Jewish pastry||Fold sides to centre and return||Open two corners||Fold sides to centre|
|Step 06||Step 07||Step 08||Step 09||Step 10|
|Lift both sides and one end of the model so it becomes 3D||Fold flap to centre||raise end||Fold flap to centre||Complete|