The kissaten katsu sando is the cutlet sandwich as the old coffee house makes it, and the difference from the famous versions is one of register, not recipe. A kissaten is the traditional neighborhood coffee place with a short kitchen menu, and its katsu sando tends to be homestyle: a fried pork cutlet, tonkatsu sauce, and soft white bread, plated to go with coffee rather than boxed to be photographed. Set it next to a depachika counter sandwich from a named tonkatsu restaurant and the contrast is plain. The basement version chases a graded cutlet and a flawless cross section at a high price. The kissaten version is generous, a little rough at the edges, cut to be eaten at the table, and judged by whether it is satisfying rather than whether it is immaculate.
The craft is the same set of decisions made with a home cook's priorities rather than a specialist's. The cutlet is a pork loin or fillet in panko, fried so the crust is crisp and the meat juicy, but often thicker, plainer, and less obsessively even than a restaurant's. The bread is soft white loaf, sometimes crust-on, sometimes lightly toasted on the press the kissaten already keeps for its hot sandwiches, which gives a faint warm crispness the chilled depachika box never has. The tonkatsu sauce is laid on with a free hand, sweet and tangy, sometimes with a swipe of mustard or a little shredded cabbage tucked in, which the strict versions usually omit. A good one is hot, hearty, well-sauced, the crust still crisp under soft bread, the kind of plate that suits a slow coffee. A sloppy one is a thin tired cutlet under bread that has gone damp, an under-sauced bite that tastes mostly of loaf, or a crust fried so far ahead it has slumped into greasy softness before it reaches the table.
The variations track the house and its habits: some toast the sandwich on the press for a hot-sando crossover, some keep it cold and plain, some add cabbage or mustard, some run a thicker cutlet on request. The specialty-shop and depachika cutlet sandwiches are a meaningfully different and more exacting build, and each deserves its own article rather than being crowded in here.