Japan isn’t
opposite Brazil.

Okinawa Island lands in south-western Paraná: Naha near Honório Serpa, Okinawa City near Clevelândia, Uruma and Nago near Palmas. The Amami islands fall on the highlands of Rio Grande do Sul and Santa Catarina, Amami itself near Bom Jesus and Tokunoshima near Cerro Negro. The Miyako and Yaeyama islands reach eastern Paraguay: Ishigaki lands 21 km from Curuguaty, in Canindeyú. Korea’s Jeju comes down in the far south of Brazil, by the lagoons near the Uruguayan border.

And the rest of Japan? Kyushu faces the Atlantic off Rio Grande do Sul, and Tokyo, Osaka and the main cities are hundreds of kilometres further out. From Tokyo the nearest exact spot is in the islands south of Kyushu, 1,122 km away; from Sapporo it is on Sakhalin, whose twin is South Georgia. Seoul and Busan miss too, and so do Brazil’s big cities: São Paulo faces the Philippine Sea, 243 km from land, and Curitiba is a sloppy sandwich, 66 km short.

Every Japanese city above 700,000 people and every Korean city above a million, with every town of Okinawa, Amami, Miyako and the Yaeyamas above 10,000 and every town of Jeju. On the other side, the cities of southern Brazil above 150,000 and the state capitals, and the cities of Paraguay, Uruguay and north-eastern Argentina, each listed if its other slice lands in or off Japan or Korea within 150 km of land, or it is a capital or a city of a million. Exact means land opposite land at the city’s own point; where the other slice would get wet, the table gives the nearest spot from which an exact sandwich is possible.

No two towns here are within a kilometre of each other’s antipode, but every town in Okinawa and Jeju is exact, and several land within a few kilometres of a Brazilian or Paraguayan town. Naha and Honório Serpa, and Jeju City and Santa Vitória do Palmar, are about ten kilometres apart.

A sandwich’s elevation bonus is the height of one end plus the height of the other (Sandwich Law § 1.4). The Board scores it the way the map shows it: from the average height of the ground over cells about 20 km across, so every spot in a cell scores the same and you only need to be in the right cell, not on the summit. These are the corridor’s best cells, one per area, each with dry land at both ends.

1. +1,040 m8 km from Naze (Kagoshima)cell average 40 m40 km from Capão Alto (Santa Catarina)cell average 1,000 m
2. +960 m5 km from Onna (Okinawa)cell average -40 m11 km from Palmas (Paraná)cell average 1,000 m
3. +480 m8 km from Seogwipo (Jeju-do, South Korea)cell average 520 m27 km from Santa Vitória do Palmar (Rio Grande do Sul)cell average -40 m
4. +240 m17 km from Shirahama (Okinawa)cell average 40 m40 km from Guajayvi (San Pedro Department, Paraguay)cell average 200 m

This is the lowest corridor: Okinawa’s hills are gentle and the islands’ cells are mostly sea level. The height comes from the Brazilian end, where the Serra Geral of Santa Catarina and Paraná rises to about a kilometre.

The window. Both slices must go down within five minutes of the same UTC instant (Sandwich Law § 2.1). The sandwich lobby holds you to it: when the first slice lands, the other side has five minutes.

The clocks. Japan and Korea keep UTC+9; southern Brazil keeps Brasília time, UTC−3, and so do Paraguay and Uruguay. Nobody changes their clocks, so the gap is 12 hours all year: noon in Naha is midnight in Paraná.

The light. Two exactly opposite points are never in daylight together: sunrise at one end is sunset at the other. The atmosphere bends a little sunlight over the horizon, so twice a day, on a clear flat horizon, the sun is up at both ends at once for eight to nine minutes. Put the bread down then and both photographs get golden light, one at dusk and one at dawn.

The seasons. Opposite. Okinawa’s typhoons come in late summer and autumn; the Brazilian highlands where it lands can see frost in July.

This corridor has something no other has: a community already on both sides. Brazil is home to the largest Japanese community outside Japan, Paraná is one of its heartlands, and many Japanese-Brazilian families have roots in Okinawa. Write in Japanese and Portuguese, with your town and its antipode; Okinawan and Japanese associations in Brazil are a natural place to start.

Then open an attempt in the sandwich lobby. It gives you a code and a link to send through whatever channel you already share, shows both slices when they arrive, and runs the five-minute window. Much of the Brazilian side is farmland, so put the bread on public ground, a roadside, a square or a park, or ask whoever owns the field. The exact grade allows a kilometre of slack, which is usually enough to find somewhere you are allowed to stand.

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