Peel the daikon and cut it into 1-inch pieces. Trim the corners of each piece so that the edges are not sharp. This will prevent the daikon from breaking apart when cooking.
In a pot, add cold water, daikon, a handful of rice (approx ¼ cup), and 1 tsp salt. Boil until a skewer can go through the daikon. This will remove the bitterness from the daikon. Remove the daikon from the water. Keep the water.
Cut konjac blocks into smaller triangular pieces. Put it into the water (from step 2) and bring it to a boil. Remove the konjac and set it aside.
You can cut the bigger fish cakes in half (optional). Put the chikuwa, fish cakes, and fish cake sheets in the water. Boil for 1 minute to remove excessive oil. Remove and set them aside. You no longer need the water.
Wash the mushrooms. Set aside.