Oden is a traditional stewed dish which uses several ingredients such as vegetable, fish cakes, egg, meat, tofu and etc. This is a typical food eaten in winter time at home and at oden stands; indoor and outdoor. Also oden can be found at almost all convenience stores throughout Japan. usually it is stewed next to the cashier.
Oden uses a stock made from kombu kelp seaweed and bonito flakes. Then, use two types of ingredients; 1 - already cooked = fish cakes, tofu products or konjac(Konnyaku) and 2 - raw = egg, daikon white radish, or beef tendon. Also some places offer oden sausage or oden rolled stuffed cabbage too.
Also there are the difference between the regions, for example wheat based Chikuwabu(you can found it the picture) is eaten mostly in Tokyo and the Eastern part of Japan and hardly to find in Osaka.
Due to oden is a popular dish during winter time, prefered to be accompanied with hot sake. Then, usually the hot sake will be served into a glass, rather than ceramic small cup.