Walk into an old Japanese kissaten in the slow part of an afternoon and the mixed sando arrives the way the room itself feels: unhurried, a little formal, plated rather than handed over. This is the coffee-shop mixed set, and on the plate you usually find three things working together. There is egg, soft and yellow. There is ham, thin and pink against white bread. There is cucumber, cool and faintly grassy, cut so the rounds sit flat. The crusts come off, the triangles get arranged like a small fan, and a curl of cabbage or a sprig of parsley keeps them company. A pour of strong coffee waits beside it. The whole arrangement is a quiet argument that lunch can be a sit-down event even when it is only bread.
The craft sits in the contrast and in the bind. Bread is soft shokupan, sliced thin so the fillings lead and the crumb yields without fighting. The egg portion is either a folded sheet of atsuyaki tamago or a creamy egg salad bound with Japanese mayonnaise; either way it should taste of the egg and not of the seasoning. Ham is laid in single clean layers with a thin film of mayonnaise and sometimes a wisp of mustard, never stacked into a slab. Cucumber gets salted briefly and patted dry so it stays crisp and does not weep into the crumb. A good plate stays distinct: each third tastes of one idea, the cuts are square, the bread is dry to the touch. A sloppy one bleeds, the cucumber goes limp, the mayonnaise pools, and the three sandwiches collapse into one wet flavor. The point of a mixed plate is variety in three bites, so the borders between the thirds matter as much as the fillings.
Variations follow the house and the season. Some kissaten swap the ham for tuna mayonnaise, or add a fourth triangle of potato salad or ham-and-cheese to widen the spread. Others toast the bread lightly so the edges crackle while the centers stay tender, which moves the plate closer to a hot sando without abandoning the cold-set idea. A summer plate might lean harder on cucumber and tomato; a heavier one might fold in a slice of cheese behind the ham. There is also the morning service tradition, where the mixed sando comes free with coffee before a certain hour, which shaped how generous and how plain the standard version tends to be. The pure egg version, when a kissaten takes its egg seriously and piles it high, deserves its own article rather than being crowded in here.