01 - Rinse sushi rice thoroughly under cold water until water is 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 steam, covered, for 10 minutes. Keep covered until ready to use.
02 - In a small saucepan, heat rice vinegar, sugar, and salt over low heat until dissolved. Gently fold the mixture into steamed rice while fanning to cool, ensuring grains remain intact.
03 - Slice imitation crab sticks into thin strips and combine with Japanese mayonnaise in a bowl, mixing until well coated.
04 - Place a bamboo sushi mat on your work surface and cover with plastic wrap. Position a sheet of nori, shiny side down, on the mat. With damp hands, evenly spread approximately 1/2 cup of seasoned sushi rice across the nori, leaving a 3/4 inch border at the top edge.
05 - Sprinkle tempura flakes and sesame seeds over the rice layer. Gently flip the nori so the rice faces down on the mat.
06 - Along the bottom edge of the nori, arrange a narrow row of crab-mayo mixture, followed by sliced avocado and cucumber.
07 - Using the bamboo mat, roll the sushi tightly from the bottom, securing the fillings and shaping firmly. Apply gentle pressure to seal.
08 - With a sharp, wet knife, cut each finished roll into 6 even pieces. Wipe blade with damp cloth between cuts for clean edges.
09 - Top each slice with additional tempura flakes for extra texture. Serve immediately alongside soy sauce, pickled ginger, and wasabi.