One flight up from a glamorous stretch of Madison Avenue you'll find serenity and sheer culinary bliss in this jewel box, which seats a mere 50. Three prix-fixe kaiseki menus consisting of five to ten small courses of chef Hitoshi Kagawa's premium Japanese fare are paired with exceptional teas and/or sakes (for an additional charge). Many of the teas are available for sale in the elegant shop downstairs. Lily bulb soup with eel dumpling is sumptuous enough, and the sashimi course is supple, but black cod roasted in a salt crust with tea leaves and dill is unforgettably fragrant, tender, and juicy. All this indulgence comes at a price, but you'll leave feeling restored. Subway: 6 to 68th St./Hunter College.