"To err is human. To loaf is Parisian," said the French writer Victor Hugo. Although seasoned in erring and loafing, I cannot attest that he nailed Paris. But loafing is tres a la mode in Kagurazaka, a shopping and dining area in Tokyo's Shinjuku Ward that is famed for its touch of French culture.

As I sit here at Cafe Paul, a patisserie whose croissant aux amandes some people might trade for revealing state secrets, I look out at the passing flaneurs, waiting for the mysterious Megumi. She is an old friend who lives down the street, and just announced she is moving to Paris. The news intrigue: a rendezvous is in order. A Frenchman must be in the picture, no matter that Megumi is married. Or is she?

Kagurazaka is Tokyo at its best — uniquely atmospheric, a mix of old Japan and cosmopolitan chic. During the Edo Period (1603-1868), many samurai lived in the area, which bordered the outer moat of Edo Castle. In 1857, the Kagurazaka district, by then popular for its "floating world" entertainments, was declared by the government as hanamachi, an official geisha quarter.