Cook the Japanese rice. Instructions are on a separate page. Please check the link above.
Prepare the fillings. Remove the seeds and cut into bite-sized pieces. Season the salmon with salt (more is better) and grill it the way you like it. Drain off all the oil from the tuna and mix well with mayonnaise, salt, soy sauce, and black pepper. Soak dried wakame in water to soften, then chop into small pieces. Season rice with chopped wakame seaweed, white sesame seeds, salt, and soy sauce and mix well. Add grilled salmon, green onions, white sesame seeds, sesame oil, salt and soy sauce to rice and mix well.
Wet your hands with water so that the rice won’t stick. Put some salt on both hands and spread it all over.
Place the steamed rice on your hand (You can do it on a cutting board just like I did in my video. ) Put your favorite filling on the rice and push the filling into the rice lightly. (You don't need to put filling for wakame and grilled salmon and spring onion onigiri)
Hold the rice between your palms. Form the rice into the triangle by pressing lightly with your both palms. Be careful not to squeeze too tightly. Rotate and then squeeze. Please check out the video for more details.
Wrap the rice ball with a strip of nori if you want.