Oshi Sushi

Oshi sushi, or oshizushi, is pressed sushi from Japan's Kansai region, especially Osaka, made by compressing vinegared rice and toppings in a wooden box called an oshibako. Once unmolded, it is cut into clean, uniform rectangles or squares.

Line the box with plastic wrap or a leaf, spread a layer of seasoned sushi rice, add the topping, press down firmly with the box's lid, then unmold and slice. The pressure gives every piece the same neat shape, which is why the mold is the defining tool of this style.

The style developed in Osaka before modern refrigeration, so toppings were cured, cooked, or marinated to preserve them, unlike the raw-fish nigiri of Edo (Tokyo). This is why classics like battera use vinegared mackerel that is lightly cured.

Battera is Osaka's most famous oshizushi: vinegared saba (mackerel) pressed over rice in an oshibako, often finished with a thin layer of kombu on top. It remains a signature item in Osaka's sushi shops and department store food halls.

Nigiri is shaped by a chef's hand piece by piece, and temari sushi is rolled into balls in the palm or plastic wrap, while oshizushi is pressed in a box and then cut into multiple pieces at once. The pressed style is the oldest of the three traditions.