Our family loves dining at Japanese steakhouses, and we usually find ourselves at one 2-3 times per year. When traveling, it's always a good bet, because we've never had an experience in which the restaurant couldn't provide a safe gluten-free meal.
By nature, tepanyaki-style dining is very gluten-free friendly. Only oil or butter and lemon are used for the grilling of meats, vegetables, and rice on the tabletop grill in front of you.
Simply call ahead to ensure they have gluten free soy sauce (or tamari) on hand. If not, you can always bring your own. This particular Benihana in Newport Beach (as well as another Benihana we've visited near our home in northern Virginia) had gluten free soy sauce (Kikkoman). We always request that it be used for the whole table, to simplify things for the chef and to reduce any mix-up in the preparation of the meal. You cannot tell a difference at all in the flavor of the food. Gluten free soy sauce tastes no different than regular soy sauce.
The two dipping sauces offered at Benihana (a mustard sauce and ginger sauce) are NOT gluten free, but frankly, you don't need any extra sauce/flavor for the food. It is so good just the way they grill it with a bit of the gluten free soy sauce.
I love this restaurant as a fun place to take the kids -- whether it's with the extended family or a large group of friends. It's also a good value for the money, and there are plenty of choices of meat and seafood -- as well as many combinations of meats -- so whatever you are in the mood for, you can order it at Benihana.