01 - Rinse sushi rice under cold water until the water runs clear. Combine rice and water in a saucepan and bring to a boil. Cover, reduce heat to low, and simmer for 15 minutes. Remove from heat and allow rice to steam, covered, for an additional 10 minutes.
02 - In a small saucepan, combine rice vinegar, sugar, and salt. Heat gently, stirring until sugar and salt dissolve. Drizzle seasoning over the cooked rice and fold gently while fanning to cool.
03 - Cut imitation crab sticks into strips and mix with Japanese mayonnaise until evenly coated.
04 - Lay a bamboo sushi mat on the work surface and cover with plastic wrap. Place a sheet of nori, shiny side down, on the mat.
05 - With wet hands, evenly spread about 1/2 cup sushi rice over the nori, leaving a 3/4 inch border at the top edge.
06 - Sprinkle the rice surface with tempura flakes and both sesame seeds. Carefully flip the nori sheet so the rice faces downward.
07 - Place a line of crab-mayo mixture, sliced avocado, and julienned cucumber along the bottom edge of the nori.
08 - Using the bamboo mat, roll up the sushi tightly from the bottom, gently tucking in the fillings as you roll. Press along the seam to seal firmly.
09 - With a sharp, wet knife, slice each roll into 6 equal pieces for even presentation.
10 - Top each sushi slice with additional tempura flakes for extra crispness. Serve with soy sauce, pickled ginger, and wasabi on the side.