The wooden tub traditionally used to mix and cool sushi rice is a hangiri. Also called a sushi oke, it is a broad, shallow, flat-bottomed wooden tub designed for the final preparation of sushi rice.
After rice is cooked, it is transferred to the hangiri and mixed with sushi seasoning, usually rice vinegar, sugar, and salt. A shamoji, or wooden rice paddle, is used to fold and toss the grains while helping release heat and excess moisture. The rice is then covered with a cloth as it cools to the temperature needed for shaping sushi.
Traditional hangiri are commonly made from cypress and reinforced with copper bands. Their size ranges from roughly 30 centimeters for home use to about 1 meter for restaurant preparation. The wood’s broad surface helps spread the rice into a thin layer, encouraging rapid, even cooling.
The alternatives listed are different tools. A makisu is a bamboo rolling mat, while a sudare is another type of woven bamboo mat. A bamboo mat cannot replace the hangiri’s role in seasoning and cooling a large batch of sushi rice.