My girlfriend and I went to Koji on a friend's recommandation. We are avid lovers of Japanese cuisine and we were not disappointed! The restaurant is located a little off central London but is well worth the trip. Service was friendly but professional and our waitress was quite helpful in selecting menu items. The decor is modern, well integrated and absolutely not ostentatious and contributes in making the restaurant's ambience convivial. I really enjoyed the Turbot Ceviche, Steak Tartare and definitely the Miso Lamb collets! Nigiris and Sashimis were absolutely perfect and melted in your mouth. What also caught my eye was the very well tough off wine list. It is extensive and well balanced between well know appellations and "outside the box" producers and regions. We were advised on a white wine from Corsica that was absolutely lovely by someone I believed to be the owner. All in all a great evening! I don't know London enough to say if it is its best Japanese restaurant, but it is surely the best I've tried and one of the best restaurant I've been in London. We will definitely return on our next visit to the City!