I went a couple months ago, but when I went I had a pretty fluent Japanese speaker with me to translate my needs (I was on a school trip) the people there offered to scrub the grill to make sure it was clean. They said that their might be a little left but that was fine with me because my reaction has gotten less and less.
I Ordered a buckwheat crepe and it came out pretty fast. It was my first time having a crepe and it was delicious. I ended up going back after a couple days and got two more.
Don’t recommend to the really sensitive, but go ahead if your fine with a small possibly for cross contamination