Short-grain rice
Japanese short-grain rice, often sold as sushi rice, which cooks up soft and slightly sticky.
This means Japanese short-grain rice, which holds together when cooked while staying tender and distinct in the grain. It is sold as sushi rice in many larger supermarkets, in any Asian grocery and by mail order.
Substitute:
Californian medium-grain rice comes very close and is often cheaper. Pudding rice is also short-grain but turns too soft and mushy, and risotto rice keeps a firmer core; both are only a stopgap, while long-grain rice such as basmati or jasmine does not stick and will not work.