Rinse sushi rice under cold water until clear. Combine with water in a medium pot, bring to boil, cover, reduce heat, and simmer for 15 minutes. Let sit off heat for 10 minutes.

In a small bowl, mix rice vinegar, sugar, and salt till dissolved. Fluff the rice and fold in the mixture for even distribution.

Press the seasoned rice into a greased baking pan, cover with plastic wrap, and refrigerate for at least 4 hours or overnight.

Cut the chilled rice into 2-inch squares with a sharp knife.

Heat oil in a skillet over medium heat. Fry rice pieces for 3-4 minutes per side until golden brown, transferring to a paper towel-lined plate to drain.

Serve warm with assorted toppings like spicy tuna, avocado, or drizzle of sauce.