Rinse 2 cups sushi rice in cold water until the water runs mostly clear
Drain the rice well
Add the rice and 2 1/4 cups water to a pot or rice cooker
Let the rice soak for 20 to 30 minutes
Cook the rice until tender and the water is absorbed
Remove from heat and let it rest, covered, for 10 minutes
Mix 1/4 cup rice vinegar, 2 tablespoons sugar, and 1 teaspoon salt until dissolved
Transfer the hot rice to a large bowl
Gently fold the vinegar mixture into the rice
Fan the rice while mixing to cool it
Let the rice cool to room temperature before using