This entry is less a single sandwich than a kind of place, and it is worth treating it that way honestly. The Specialty Sando Shop describes the dedicated sandwich counters that have multiplied across Tokyo, Osaka, and Kyoto: small operations whose entire reason for existing is the sando, treated with the focus other shops give to ramen or coffee. There is no recipe to describe here, only a sensibility, and the sensibility is what makes the category worth a page of its own.
What unites these shops is an obsessive attention to the parts the convenience case takes for granted. The bread is usually a high-grade shokupan, sometimes baked in-house, sliced to a thickness the shop has decided on deliberately. The fillings are built rather than scooped: egg salad with the yolk and white handled separately for texture, cutlets fried to order, fruit arranged so the cross-section is symmetrical when the sandwich is cut. The craft is visible in the cut itself. A specialty shop sando is sliced cleanly so the layered interior is legible, the proportions of bread to filling tuned so neither overwhelms the other, the assembly tight enough to hold its shape on the plate. A weak imitation gets the photogenic cross-section but not the eating: the filling under-seasoned, the bread merely soft instead of structured, the balance off so it reads as a prop rather than a sandwich. The whole proposition rests on the idea that a sando repays the same precision as a more obviously serious dish, and the good shops prove it while the lesser ones only photograph it.
The experience is part of the product. These counters tend to be small, design-conscious, often with a short menu and a queue, and the sandwich is frequently presented for its cross-section as much as its flavor. That presentation can tip into spectacle, and the honest read is that some shops lean harder on the photograph than the palate. The strongest of them hold both at once.
Variations are really variations of focus. Some shops specialize in the fruit sando, treating it almost as confectionery. Others build their identity around the katsu sando and the cut of pork or beef inside it. A few stake everything on the egg sando, or on seasonal fillings that rotate with what is good that month. The constant is the format taken seriously and the convenience-store sando refined upward into something deliberate. How the Japanese sando climbed from the train platform to the design-led specialty counter is a broad subject that deserves its own article rather than being crowded in here.