Rinse sushi rice under cold water until water runs clear, then cook according to package instructions. Fluff rice and mix in salt and optional furikake. Allow to cool slightly.

Cut chicken into small pieces. Marinate with soy sauce, sake, baking soda, and cornstarch. Mix well and refrigerate for at least 30 minutes.

Whisk together soy sauce, mirin, and brown sugar to make teriyaki sauce. Set aside.

Heat oil in a frying pan, add chicken, cook for 2-3 minutes until browned. Add garlic, sauté for 30 seconds, then stir in teriyaki sauce until thickened.

Scoop rice into palm, create a well, fill with chicken, top with more rice and shape into a triangle. Wrap with nori.

Arrange on a plate, serve with teriyaki sauce or soy sauce for dipping.