Both Udon and Oden are Japanese dishes that are more popular in cold weather. They may be a bit confusing for Japanese learners, but you don’t want to mix them up when you want to order the food in a restaurant in Japan.
This is Udon.
Udon is a Japanese noodle that is made from wheat flour. They can be served hot or cold and with or without soup. The ingredients of Udon soup and toppings are very wide. One of the most common soups is clear soup from bonito and seaweed broth, and sometimes they are in Miso soup or even curry soup. We have different types of noodles in Japan. Udon noodles are white and thicker than others.
This is Oden.
Oden is a type of Japanese Nabe (hot pot). There are a variety of ingredients simmered in a bonito and seaweed broth, such as eggs, daikon radish, fishcakes, beef tendon, mochi (rice cakes), Konjac.
It looks like a big pot of soup, but we normally eat the ingredients only, not the soup stock. They are often served with Japanese mustard. Oden is so popular in winter that you can easily find it in restaurants, izakaya, standing bars or even convenience stores. You may be able to order a single ingredient Oden and it could be as cheap as 100 yen.