The most popular dish, as at any unagi restaurant, is unaju — grilled, soy-basted eel laid out on a bed of rice in an ornate lacquer-look box. The soft, melting texture of the fish; the savory tang of the basting sauce; a light dash of tongue-tingling sansho pepper; the neutral, comforting backdrop of that steaming white rice — this is gourmet fare that we all can afford.