In a bowl, mix the drained salmon, KEWPIE Mayonnaise, finely chopped red onion, and soy sauce. Season with salt and pepper to taste. Set aside.

Place a nori sheet on a flat surface, rough side up. Using scissors, cut the nori sheet from one edge halfway towards the center.

Spread ? portion of the rice on the bottom right quadrant of the nori.

On the top left quadrant, layer ? portion each of cucumber slices, salmon stuffing, and avocado slices.

Fold the bottom left corner of the nori over the fillings.

Continue folding over the rice to create a square package, using the cut in the nori to help it fold neatly.

Wrap tightly in plastic wrap to hold its shape.

Repeat the process to make a total of 4 Onigirazu.

Let the Onigirazu rest for a few minutes to set.

Remove the plastic wrap and cut each Onigirazu in half diagonally before serving.