Fantastic modern and cool Japanese in MayfairKoyn is a cool and contemporary Japanese culinary institution in the heart of upscale Mayfair. I think Nobu has originally inspired its cuisine even though it is original as itself, too. Very good wine cellar. Try the salmon tataki in mustard sauce, waguy fim sungs, Japanese beef tenderloin. Very nice desserts too, which is not that typical for Japanese restaurants. Very expensive but worth it.