Place the rice into a mixing bowl and cover with cool water. Swirl the rice in the water, pour off, and repeat until the water is clear, 2 to 3 rinses.
Place the rice and 2 cups of water into a medium saucepan and place over high heat. Bring to a boil, uncovered. Once it begins to boil, reduce the heat to the lowest setting, and cover. Cook for 15 minutes. Remove from the heat and let stand, covered, for 10 minutes.
Combine the rice wine vinegar, sugar, and salt in a small bowl and heat in the microwave on high for 30 to 45 seconds. Transfer the rice into a large wooden or glass mixing bowl and add the vinegar mixture. Fold thoroughly to combine, coating each grain of rice with the mixture. Allow to cool to room temperature before using to make sushi or sashimi.