Soup base of dashi and mugi miso (barley miso)
ingredients: tofu cubed, wakame, green onions, enoki/shimeji, clams are great too, and rice. Yup, rice.
In Japan they refer to the mixing of rice in your miso soup as "nekomama". I've been told that this is because they feed the leftovers to their cats. As such, this is a rude way to eat your miso soup at some establishments that would be insulted by that. Try it though, nekomama is the best.