Rinse sushi rice under cold water until water runs clear. Cook according to package instructions with about 2 cups of water until tender and sticky.

Transfer cooked rice to a bowl while warm and gently fold in rice vinegar, sugar, and salt.

Slice cucumber, avocado, and carrot into thin strips while the rice cools.

On a bamboo mat or clean surface (shiny side of nori down), wet your hands and spread an even layer of rice over three-quarters of the nori sheet.

Place prepared veggies in a line across the center of the rice-covered nori.

Starting from the bottom edge, roll tightly while tucking in the filling. Seal the edge with water.

Slice rolls into bite-sized pieces using a damp knife and serve with soy sauce.