Cut the daikon into four thick rounds and peel the skin off. Score one side with a cross, about 1 cm deep to prevent the daikon from falling apart when simmering for a long time.
Boil the daikon in water with ¼ cup rice for about 15-25 minutes.
Soak the konjac in water to remove any bad odor, then cut it into triangles.
Pour water into a large pot and bring to a boil. Add the soy sauce, mirin, sugar, oyster sauce, dashi powder, and 1 ½ teaspoons salt. Bring to a boil.
Lower the heat to medium-low and add the chicken legs, then add potatoes, daikon, konjac pieces, and half of the shrimp dumplings to make the broth tasty.
Add fishcakes, mochi kinchaku, and other soft ingredients toward the end.
When the meat has cooked through, the soup is done. It takes about 20-25 min.
Serve and enjoy with Japanese mustard Karashi.