Slice the kombu into very thin slivers and place in the bottom of a heavy skillet. Reserve kombu soaking water. Remove the dried daikon, squeeze out water and slice. Reserve the soaking water. Place the daikon on top of the kombu. Remove dried tofu, squeeze out water, slice into strips and place on top of the dried daikon. Discard dried tofu soaking water. Remove shiitake from soaking water and place on top of the dried tofu. Reserve shiitake soaking water. Remove lotus root, chop coarsely and place on top of the shiitake. Reserve lotus root soaking water. Layer the onions, sweet corn and carrots on top of the lotus root. Add water, including the vegetable soaking waters, to just cover the dried daikon, about 3 cups. Cover the skillet and bring to a boil. Reduce the flame to medium low and simmer for about 30 minutes. Add shoyu, cover and simmer another 5 minutes. Remove the cover, turn the flame to high, add the scallions, and cook off most of the remaining liquid, stirring occasionally. Remove and serve.
Per serving - 100 calories, 1 g fat (9% calories from fat), 7 g protein, 24 g carbohydrate, 10 g fiber, 0 mg cholesterol, 324 mg sodium