Having glamourised the noodle bar (Wagamama) and Cantonese cooking (Hakkasan and Yauatcha), restaurateur Alan Yau has added his stamp to smart Japanese restaurants in London. When it opened, Sake No Hana (meaning 'sake flower') was being touted as the new Nobu and it certainly has the right clientele. Yau's partner is the Aeroflot heir Evgeny Lebedev, making it a favoured haunt for Russian oligarchs, their high-maintenance arm-candy and their money-buys-class attitude. The room, which soars upward like a modernist Japanese forest of blond wood and bamboo, oozes a cold luxury, while the staff are so glam it's hard to tell who's dining and who's serving. As the name suggests, sake is the thing to drink (in any case, the only wine on the menu is champagne, starting at £30 for a glass of Krug; cf money/class) and there are 60 varieties, chosen by sake sommelier Stuart Hudson. Alongside sushi, sashimi and home-style braises, the menu is studded with the sort of prestige ingredients - wagyu beef (£70 a pop) and white truffle rice - that get plutocratic pulses racing. Alas, quality varies from mediocre to merely good and it all comes without much explanation which can be baffling. If you're going to take pot luck, make sure your wallet can handle it.