I'm not a vegetarian, but my wife is vegan, so we were really excited to find an udon shop with a vegan option. We went to the restaurant, confirmed that they could make a fish-free, meat-free broth, and had a great meal. We returned again and, this time discovering some kamuboko (fish cake) in the broth, but they apologized, swapped it for new soup, and everyone was, once again, very happy.
Yesterday we went for visit number 3, and the vegetarian waitress informed us that they do not have a veggie broth option. She checked with the kitchen, and as she suspected, we've been eating fish broth the whole time. This is really unfortunate, because the previous review and the assurances of the staff had billed it as a rare vegan-friendly standout.
My wife opted for some veggie sushi, edamame, and tempura veggies (apparently, there's no egg in their batter), and we still had a great time. The owner is a really attentive, nice man, and the staff is great. For you carnivores out there, the sushi is also excellent. Just watch out for the broth if you're a vegetarian/vegan.
Cons: Soup not vegan as sometimes claimed