Preheat the oven to 375°F (190°C).
Cook the sushi rice according to package instructions.
Mix rice vinegar, sugar, and salt in a bowl, and gently fold into the cooked rice.
Shape the wonton wrappers into cones.
Bake the wonton cones for 10-12 minutes, or until golden brown.
Fill each cone with sushi rice, fish, avocado, and cucumber.
Add nori strips as desired and garnish with sesame seeds.
Serve with soy sauce on the side for dipping.