Our favorite French pastry shop is run by a Japanese chef, Terai Norihiko, who studied in France and Belgium and opened a small shop called Aigre-Douce, in the Mejiro neighborhood. Aigre-Douce is a pastry museum, the kind of place where everything looks too beautiful to eat. On her first couple of visits, Iris chose a gooey caramel brownie concoction, but she and Laurie soon sparred over the affections of Wallace, a round two-layer cake with lime cream atop chocolate, separated by a paper-thin square chocolate wafer.