Mix flour, dashi soup, and eggs in a bowl to make batter. Thickness of the batter should be like potage soup. Preheat a takoyaki pan and grease the molds. Pour batter into the molds to the full. Put octopus, red ginger, green onion, and dried red shrimp in each mold. Grill takoyaki balls, flipping with a pick to make balls. When browned, remove takoyaki from the pan and place on a plate. Put sauce and mayonnaise on top and sprinkle bonito flakes and aonori over.