Had lunch here today. After having a chat with the manager who was really excited to try to feed me, I ordered the bean and spinach curry with rice. It was rather tasty. As others have mentioned, not sure about cross contamination, I have fairly light symptoms and didn't feel sick at all. Being able to eat was a pretty nice feeling.
I did not get sick while eating their mild butter chicken curry and rice. But I am not confident to say that it is 100% celiac friendly. Seperate menu: They have a seperate menu that lists out their dishes and whether it contains wheat, milk, nuts, egg, and seafood. Options: there were 3 choices of curry to choose from. Waiter: seems somewhat knowledgeable about gluten, but was not able to instill confidence in me about what is safe to eat or not. He gave me a complimentary salad and said it was gluten free, but did not know what was in the salad dressing besides cream.
They have a good allergen guide, just ask for it. Lots of gf tandoori options and a few curries available. Four stars because portions were small for the price (600 yen for 3 tandoori chicken pieces), but the food itself was delicious. Small kitchen and they're making naan on site, handling dough in view of the restaurant, but I have celiac dz and I was fine.
I stayed at the Hotel Gracery and this restaurant is in the same building on the first floor. They do not have a gluten free menu, but when I asked the waiter, he did say that both dishes did not have any wheat in them. I took a chance since there aren't many GF restaurants around. I ended up having dinner here twice. The butter chicken with rice and the curry chicken with rice were both good and I didn't get sick. Staff was very friendly.