Rinse rice until the water runs clear and drain the rice well. To make rice in the Instant Pot, add the rice to the inner cooking pot then add water. Equal parts rice to water. Let soak for 30 minutes.
Close and lock the lid, making sure the steam knob is on Sealing/Locked. Pressure cook on high for 4 minutes.
Meanwhile, in a medium bowl, combine the crab, mayo, salt and green onions. Set aside.
Once the pressure cooking is done, natural release the pressure for 10 minutes. Then quick release the remaining pressure.
In a small bowl, heat up rice vinegar in the microwave and dissolve sugar and salt. Add the liquid to the cooked rice and mix well.
In a 9 inch x 13 inch baking pan or casserole dish, evenly spread the rice in a flat layer covering the bottom of the pan or dish. Evenly sprinkle furikake over top.
Evenly spread the crab mixture on the rice.
Place the avocado slices in a single layer on top of the crab. Zigzag Japanese mayo over top. Top with remaining green onion, tobiko, furikake and roasted sesame seeds.
Serve with nori seaweed.