Reading Jay Rayner's restaurant review just now I saw the bit below. Now I think Jay lives in one of the leafy streets near Clapham common* so may be doesn't get out to rougher bits of town but I think he may need to take more water with his sake as his description of Hanway st makes it sound like "last exit to Brooklyn" rather than a slightly down at heel short cut with a wonderful "tapas" bar and an excellent record shop (JB's) anyway here's his description of that bit behind virgin!
"A simple wish list, then, which narrowed it down a bit, particularly in London. The restaurant I wanted, I was told by knowledgeable friends, was Kikuchi in Hanway Street just off Tottenham Court Road - the sort of dank, hidden alley that TS Eliot might have been thinking of when he wrote in The Love Song of J Alfred Prufrock of "certain half-deserted streets, The muttering retreats of restless nights..." Hanway Street is the kind of place you go for a quiet nervous breakdown, to contract a notifiable disease or, as it turns out, for very good sushi."
Here's a bit of history of the place including a bit about the first man in london to use an umbrella!
* Update: see comments for JR postcode clarification!