Season the salmon with 1/4 teaspoon of salt and 1 teaspoon of sake, and let it sit for 5–10 minutes. Peel and slice the ginger root into very thin matchsticks, then set aside.
Wash the rice and drain all the water, then place it in the rice cooker's removable bowl. Add salt, soy sauce, mirin, and sake, then add enough water to reach the line for 2 cups of rice. Mix in the sliced ginger, then place the seasoned salmon fillet on top. Cook as you would regular white rice.
Cook the edamame in boiling water with a pinch of salt. Shell them afterward, or use pre-shelled beans.
Once the rice is done, fluff it with a spatula, breaking the salmon into small pieces. Mix in the edamame, then let it rest for 10 minutes before serving.