The staff is very knowledgeable, and if your waiter/waitress doesn't have an answer they are more than willing to find out for you.
They don't have their menu marked, I called ahead and the nicest employee told me all of their sushi/sashimi is safe to eat. (Excluding tempura) To avoid all of their fried foods, hot foods and sauces as they all contain a wheat based soy sauce. Which if you're looking to get your fill of sushi is definitely not a problem.
Additionally they do offer a gluten free soy sauce upon request and they also encourage you to bring your own if you'd like.
— No gluten-free information on the menu