What is the name of the wooden box used for making oshizushi?

The wooden box used for making oshizushi is called an oshibako. Its name literally means “pressing box,” describing the way it compacts rice and toppings into a firm block.

An oshibako is traditionally assembled from a base, removable side walls, and a pressing lid. The cook places sushi rice and ingredients such as cured mackerel inside, then presses down with the lid. Once compacted, the walls are lifted away and the sushi is cut into neat pieces.

Wooden boxes are often soaked briefly in water before use, which helps prevent rice from sticking. Plastic versions are also common because they are easier to clean. The longer term oshizushihako means essentially the same thing, while makisu is a separate bamboo rolling mat used for rolled sushi rather than pressed sushi.