For the sushi rice: Wash the rice several times until the water runs clear. Cover the rice with cold water and soak for 20 minutes. Drain and place the rice in a rice cooker. Add 3-3/4 cups water. Cover and cook until the water is absorbed. While the rice is cooking, combine the rice wine vinegar, mirin and sugar in a small saucepan and cook over low heat until the sugar is dissolved. Remove from the heat. When the rice is cooked, remove from the cooker and place in a large wooden bowl. Using a rubber spatula, fold in the vinegar and sugar mixture. When the vinegar mixture is folded in, cover the bowl with a damp towel and let rest for 30 minutes.
For the sambal aioli: In the bowl of a food processor or blender, combine the lemon juice, sambal, garlic and egg yolks and process until combined. With the processor running, slowly drizzle in the canola oil to create an emulsion. If the aioli needs to be thinned out after all of the oil has been added, thin with a little water or lemon juice. Season with salt and pepper.
*RAW EGG WARNING
Food Network Kitchens suggest caution in consuming raw and lightly-cooked eggs due to the slight risk of Salmonella or other food-borne illness. To reduce this risk, we recommend you use only fresh, properly-refrigerated, clean, grade A or AA eggs with intact shells, and avoid contact between the yolks or whites and the shell.
To make the Tempura Shrimp Maki Roll: Preheat a fryer to 360 degrees F. In a large bowl, combine the rice flour, all-purpose flour and salt. Add the club soda until the consistency of pancake batter is achieved. Butterfly the shrimp by slicing lengthwise down the back. Dip the shrimp in the tempura batter and then place in the fryer and fry until golden brown, about 3 minutes. Remove from the oil to a paper towel-lined plate.
On a sushi mat, lay down 1 piece of the nori, shiny side down. Spread the sushi rice on one half of the nori, about 1/4-inch thick. Spread about 1 tablespoon of the sambal aioli over the rice. In the center of the rice, lay down 1/4 cup of the cucumber and a few strip of red bell pepper in a line that reaches from one side of the nori to the other. Top the cucumber with 3 pieces of the tempura shrimp. Sprinkle 1/4 cup of the wasabi tobbiko over the shrimp. Roll the sushi up, using the sushi mat. To seal the roll, use a little water along the edge of the nori. Cut the roll into 6 pieces. Repeat this procedure 3 more times to create 4 rolls.