Almost everything on the menu is naturally gluten free, so we always make an effort to stop at Gyukaku if we are near one. You order your meat/veggies which come to your table raw, then you pop them on the grill to cook. All three sauces on the table are GF and you can even buy bottles of it to use at home. There are a couple sauces (teriyaki and basil?) that are used on some chicken dishes, so just make sure to sub for gf sauce. For example, the kids meal comes with teriyaki chicken, and the server was on top of it and said they'd sub in the sweet soy sauce instead since I had already asked her about gluten free when ordering something else. Can't say enough good things about this place.
Pro tip: lunch time is a lot cheaper than dinner time (though dinner is still worth it!)
— Very
— Gluten-free items are marked on the main menu
— Most/All
— Excellent