Season salmon fillets with salt generously and let it sit in refrigerator at least 2 hours before cooking, preferably overnight.
Rinse rice under running cold water until the water gets almost clear. Cover the rice with fresh cold water and soak for 30 minutes. Drain the rice thoroughly in a strainer for15 minutes. Place the rice in the inner pot of a rice cooker. Add sake, mirin, and salt. Add the water up to the mark of 2 cups for Sushi Rice. Place a kombu on top of rice. Start a rice cooker.
Preheat broiler. Use paper towels, pat dry salmon fillet. Place a salmon on a rack with a sheet tray. Position the salmon about 6 inches from the heat source and broil until it flakes for a few minutes or more. It is easy to burn so watch it carefully. When it cools enough to handle, flake the salmon. Remove and discard the skin and pin bones
Once rice is ready, keep the rice cooker unopen to let it steam 10 more minutes. Discard a kombu. Fluff the rice with a rice scoop and mix in the half of salmon flakes and sesame seeds.
Divide the salmon rice into serving bowls. Place the remaining half of salmon flakes and ikura on top of the rice. Serve with nori flakes and wasabi paste if desired.