Rinse the sushi rice thoroughly in a fine mesh strainer until the water runs mostly clear.
Add the rice and water to a rice cooker and cook according to the manufacturer's instructions.
Transfer the cooked rice to a rimmed baking sheet.
Pour the seasoned rice vinegar over the rice and gently fold it in using a rice paddle or spatula. Avoid mashing the rice.
Allow the rice to cool completely.
In a small bowl, combine the Japanese mayonnaise and sriracha until smooth.
In another bowl, mix the chopped imitation crab with half of the spicy mayo mixture until evenly coated.
Divide the cooled sushi rice among serving bowls.
Top each bowl with the crab mixture, diced cucumber, sliced avocado, and chopped nori.
Drizzle with the remaining spicy mayo.
Sprinkle with black sesame seeds, toasted sesame seeds, and nori furikake.
Serve the California Roll Sushi Bowls immediately with soy sauce on the side.