This has been the best Japanese I have had in Vegas thus far. My boyfriend and I didn't have reservations either and they were kind enough to take us in last minute. Usually it's best to make reservations, especially if you are planning on dining on the weekends.
Our favorites were the grilled items: chicken breast w/ skin, beef skirt w/ garlic, pork ear, and the enoki mushrooms wrapped in bacon. The portion sizes were smaller, but just enough for you to try a good variety of items. We also ordered some of the items off the special menu: baby Japanese conch [which was too bland] and homemade fresh tofu. The tofu had a nice texture to it, I would recommend getting it half fried and normal so you get to taste both textures. If you are a fan of uni [sea urchin], I would recommend getting the sea urchin seaweed soup. The uni was extremely fresh and the soup was light enough to not mask the sweetness of the uni.
I would definitely go back to this place. Just keep an open mind when trying their items since the descriptions aren't the best. If you like a smaller environment with dishes that are unique from other places, I would recommend this place to you.