The pork menchi katsu sando is the baseline ground-meat cutlet sandwich built on pork mince specifically, and that meat choice gives it the softest, sweetest character in the family. Menchi katsu is seasoned minced meat bound with onion, shaped into a patty, breaded in panko and deep-fried; pork keeps the patty tender and a little sweet where beef sets firmer and more savory. Between soft trimmed white bread with tonkatsu sauce, the build is the standard one. What sets this version apart is a juicier, gentler center that leans homestyle and comforting rather than meaty and assertive.
The craft is in pork mince's natural tendency toward juiciness, kept in check so it does not turn greasy. Pork carries more fat and stays moist easily, so it is worked with onion and a light binder, formed into a patty, coated in fine panko, and fried until the shell is deep gold and crisp while the inside runs hot and tender. The fat is a feature here, but only to a point, and an underfried or overfat patty turns the sandwich oily. It is brushed with tonkatsu sauce, dark, fruity, sweet and tangy, which echoes pork's own sweetness. The bread is thin soft shokupan, crusts off, often buttered on the inner face so it takes the moisture rather than going limp, cut into clean pieces. The skill is in the patty bleeding a little savory fat into the bread on purpose without flooding it, and in the crust staying crisp against that moisture. Done well the eat is soft bread, a crisp shell, and a tender sweet pork center with the sauce close behind. Done poorly the patty is greasy or dry, the breading sogs and slides, and the bread tears.
Eating one is the softest and most domestic of the family, the onion and pork together giving it a sweet, home-kitchen note, the kind of thing that reads as comfort food rather than restaurant work. It is gentler than the beef build and plainer than the cheese one.
The variations sit beside it as siblings. The plain baseline uses a mixed or unspecified mince; the beef version eats firmer and more savory; the cheese version melts a core through the meat. There is also the soft-roll form, menchi katsu pan, which carries the same patty in a hinged bun for one-handed eating. The melted-cheese-core build, with its molten center and indulgent pull, deserves its own article rather than being crowded in here.