Gather all the ingredients.
Finely mince Yellowfin Tuna and place into a small mixing bowl. Do NOT use a food processor as the tuna will become too mushy.
Finely chop green onions and place into small mixing bowl.
In the same small mixing bowl, add Sesame Oil, 1 tsp Soy Sauce, Kewpie Mayo, Togarashi, Sriracha and mix well. Set aside.
Cut ends off of cucumber. Now slice cucumber long ways making 2 halves. Cut halves into 1/4's making four longs sticks from each half as shown below. Set aside.
Fill a small bowl with water. You will be using it to seal the roll.
Take soy paper and place it horizontally. Place about 3 tbsp spicy tuna mixture across the center followed by sticks of cucumber. Make sure not to overfill or the roll will not seal.
Dip your finger in the small bowl of water and wet across the farthest edge away from you.
To roll, grab the edge of the soy paper closest to you, keeping the fillings in place with your fingers, roll it into a tight cylinder.
Using sharp knife, cut spicy tuna roll into six pieces and plate. Sprinkle optional Toasted Sesame Seed and serve with Soy Sauce and optional wasabi.