01 - Rinse rice in cold water until water runs clear. Combine rice and water in a pot, bring to a boil, cover, reduce heat to low, and simmer for 15 minutes. Remove from heat and allow to steam, covered, for 10 additional minutes.
02 - Combine rice vinegar, sugar, and salt in a small saucepan. Heat until sugar and salt dissolve. Gently fold seasoning into the cooked rice while fanning it to room temperature.
03 - Slice imitation crab sticks into thin strips and mix thoroughly with Japanese mayonnaise.
04 - Cover a bamboo sushi rolling mat with plastic wrap and lay a nori sheet, shiny side down, on top.
05 - With dampened hands, spread approximately 1/2 cup sushi rice evenly over the nori, leaving a 3/4-inch border at the top. Sprinkle with tempura flakes and both sesame seeds. Gently flip nori so the rice faces down.
06 - At the edge closest to you, arrange a line of crab-mayo mixture, avocado slices, and julienned cucumber.
07 - Using the mat, roll the nori tightly around the fillings, keeping even pressure to maintain a compact log. Press lightly to seal the edge.
08 - With a sharp, wet knife, cut each roll into 6 even pieces, cleaning the blade between cuts for cleaner edges.
09 - Top each sushi piece with a pinch of tempura flakes for added crunch. Arrange on a plate with soy sauce, pickled ginger, and wasabi on the side.