1. In a small saucepan, combine ˝ cup soy sauce with 2 tablespoons of mirin (or the dry sherry) and sprinkle lightly with MSG. Bring to a boil, stirring constantly, and then pour into individual serving bowls.
2. Slice the 4 scallions crosswise into very thin rounds. Garnish the sauce with the scallions, ginger, hanakatsuo and nori, and then set it aside.
3. Cut the 4 cakes of tofu into 1-inch cubes.
4. Pass the sheet of nori over a flame on one side only and cut it into ˝-inch square pieces.
5. Following the nabe procedure (see Nabemono section), place the cooking pot of your choice on the dining table. Pour in the 6 cups of cold water, add the square of kombu, and bring to a boil.
6. Drop in the tofu and simmer gently for 2 to 3 minutes - if cooked too rapidly or too long, the tofu will harden.
7. Scoop the tofu out of the broth with a slotted spatula or spoon and place in individual bowls. Ladle a little of the broth into each bowl, and serve with the dipping sauce and garnishes.