Start by rinsing the dry sushi rice under cold water until the water runs clear; this helps remove extra starch so the rice cooks evenly. Transfer the rinsed rice and water into a rice cooker or pot and cook until tender and sticky. Once done, spread the rice onto a baking sheet to cool faster.
While the rice is still warm, pour the seasoned rice vinegar over it. Gently fold the vinegar into the rice using a rice paddle — being gentle prevents the grains from getting mushy. Allow the rice to cool completely before assembling the bowls.
In a small bowl, mix Japanese mayo with Sriracha to make the spicy mayo. Chop the imitation crab into small pieces, dice the cucumber, crumble the nori sheets, and slice the avocado. Try to keep everything similar in size so each bite feels balanced.
Add a generous layer of cooled sushi rice to each bowl. Arrange the chopped crab, cucumber, and avocado slices on top. Drizzle with spicy mayo, then finish with nori pieces, sesame seeds, and nori furikake for extra flavor and crunch.