London's innovative Japanese restaurant owes much to its founders, actor Robert de Niro and chef Nobu Matsuhisa. The kitchen staff is brilliant and as finely tuned as their New York counterparts. The sushi chefs create gastronomic pyrotechnics. Those on the see-and-be-seen circuit don't seem to mind the high prices that go with these incredibly fresh dishes. Elaborate preparations lead to perfectly balanced flavors. Where else can you find an excellent sea-urchin tempura? Salmon tartare with caviar is a brilliant appetizer. Follow with a perfectly done filet of sea bass in a sour bean paste or soft-shell crab rolls. The squid pasta is sublime, as is the black cod with miso; the latter dish is incredibly popular and with good reason. Cold sake arrives in a green bamboo pitcher. If it's featured, finish with the savory ginger crème brûlée.