After 18 years of Sag Harbor crowd pleasing, sushi pros cross over to the big island. Output divided between fresh sushi and modern Japanese cuisine. (Ringers like bulgogi slip in, too.) Chile tuna, sea bass, lobster with miso butter. Sake to pair. Flatiron outpost is bigger than the mother ship, promising to ease legendary lines. Interior has nightclub vibes, with dim lighting, earth tones, discreet wood accents.