Oysters and Chablis, steak and Malbec, lamb and Rioja. There are some classic food and wine pairings that, for whatever reason, work. For me, sushi and champagne is one of them. Now, classically in Japan sushi is eaten with beer or sake, the rice-based wine. Champagne and sake are very similar in that both are measured by their sugar levels. With sake the scale goes from +10 (very dry) to -10 (very sweet) but for champagne the scale goes from Brut Nature (very dry) to doux (very sweet). Many people think that sake should be served hot but actually the best sakes are served at room temperature or slightly chilled as heat causes many of the delicate aromas to be lost.
Richard Geoffroy, Dom Perignon's Chef de Cave, suggests that Dom Perignon is a great partner to the Japanese cuisine because the high yeast content in champagne partners well with the high yeast content in soy sauce, a Japanese staple, but I feel it works on many other levels as well. It is a natural fact that champagne is a great partner for various fish dishes because of its high acidity and cleansing qualities. Most champagnes are also relatively light in their NV forms and so do not overbear light sushi dishes like ginger marinated tiger prawns and salmon nigiri. A favourite tried and tested pairing of mine is tempura salmon maki (infact most tempura dishes) with a light chardonnay dominated champagne, like the Ruinart Blanc de Blancs NV or, if you want something different but equally mouth-watering, the Colin Grand Cru 2004 from French Bubbles.
Gosset Grand Millesime 2000 as a good partner. Its mature and honeyed with ripe, peachy fruit. The Charles Heidsieck Rose Reserve is another fleshy, gastronomic champagne that could hold its own with some heavier sushi dishes.
A word of warning though, strong flavours can kill even the richest champagnes and any heat clashes badly with acidity. This having been said... go easy on the wasabi.