Japonica short-grain white rice is the polished grain of Oryza sativa subsp. japonica, a temperate-adapted subspecies of Asian rice characterized by short, rounded grains and a cohesive texture when cooked. White rice refers specifically to rice that has been milled to remove the bran and germ layers, leaving primarily the starchy endosperm. Japonica rice varieties were likely domesticated in eastern China and later became foundational to wet-rice agriculture in Korea and Japan, where they shaped agrarian systems, ritual life, and cuisine.

As a food, Japanese short-grain white rice is prepared by washing, soaking, and steaming or boiling with measured water until tender and slightly glossy. Its relatively high amylopectin and lower amylose content compared to long-grain indica varieties produces a sticky yet distinct-grained texture suitable for chopstick use and molded preparations. It is the base for sushi, onigiri, donburi rice bowls, bento meals, and everyday table service, and it accompanies dishes such as grilled fish, pickles, and miso soup. Beyond plain rice, it serves as the substrate for sake brewing, rice vinegar production, rice crackers, rice flour confections, and koji-based fermentations. Its culinary role is especially central in Japanese cuisine but also prominent in Korean and certain northern Chinese foodways.

Chemically, Japanese short-grain white rice is composed primarily of starch, a polysaccharide consisting of amylose and amylopectin. The relatively lower amylose proportion (compared to indica rice) accounts for its cohesive texture. Because it is polished, many bioactive compounds present in the bran—such as γ-oryzanol, tocopherols, and phenolic acids—are largely removed during milling. However, it still contains small amounts of B vitamins (notably thiamine, though reduced compared to brown rice), minor proteins rich in glutelin, and trace minerals.