Gather all the ingredients.
Peel the avocado and cut into 1/4" slices longways and and then again in half short ways per picture below. You will need 24 pieces.
Cut cream cheese into 1 oz slices (using the marker on the cream cheese wrapper). Then cut into 1 oz sticks into 1/8s, so each 1 oz of cream cheese will yield 8 pieces and set aside. You will need 24 pieces.
De seed jalapeno (leave some seeds in there for the spice) and finely dice.
Drain canned crab meat from water VERY well by pressing the meat down with a spoon. There can be no water in there or it will affect the end texture. In a mixing bowl , add crab meat, Kewpie mayo, sweetener, rice vinegar, and diced jalapenos. Mix well until potato salad-like consistency.
On a plate, sprinkle toasted sesame seed and set aside.
Use a slicer to make 24 thinly sliced cucumbers long ways. Place the sliced cucumbers on top of a paper towel and use another paper towel to pat dry. Once dried, transfer cucumber slices on top of the sprinkled toasted sesame seed as pictured below.
In the middle bottom half of each sliced cucumber, place a piece of cream cheese and avocado. Follow this up with about 1/2 tsp of the crab mix as shown on picture below.
Grabbing the bottom of each cucumber, carefully roll upwards to form roll. Repeat with all the rolls and transfer to serving plate. Serve with optional dipping soy sauce.