The pages are in English; this contents, the search and the buttons are in Japanese.

The budō: judo, karate, kendo, sumo, kyūdō and the dojo

Six surfaces of the Japanese martial arts, drawn to scale from the federations' own rules: sport: "judo" (the IJF's and the All Japan Judo Federation's competition areas), "karate" (the WKF's kumite and kata areas), "kendo" (the shiai-jo), "sumo" (the dohyō), "kyudo" (the kyūdōjō, kinteki and enteki) and "dojo", the builder: a floor of tatami laid as real units, with its walls, doors, windows, shrine and seat of honour. Five famous halls are on the atlas: the Kodokan, the Nippon Budokan, the Ryōgoku Kokugikan, the old Butokuden of Kyoto and the Budokwai of London.

import { drawKyogijo, RANGES } from "@johnmorrisdotca/kyogijo-stadiums";

const judo = drawKyogijo({ sport: "judo" });
const dohyo = drawKyogijo({ sport: "sumo", budo: { tassels: true } });
console.log(judo.includes('data-sport="judo"'), dohyo.includes("ky-bud-tassel-e"));
// true true
console.log(RANGES.judo.map((range) => range.id).join(", "), "|", RANGES.kyudo.map((range) => range.id).join(", "));
// contest-area, start, half | shajo, yamichi, azuchi

Every figure is a published fact, with its rule or its page in Sources; a figure no rule gives is marked ours there and in the code. The Japanese names are the federations' own where their rules have one, and are listed in strings-ja.md. Photographs were looked at as references and nothing from one is copied.

The options are budo (BudoStyle) for judo, karate, kendo, sumo and kyūdō, and dojo (DojoSpec) for the dojo; league picks the rulebook. A compass side (north, south, east, west) names a side of the plan as it lies wide; a tall drawing turns it a quarter, as every surface turns.

Judo#

sport: "judo". The default is the IJF's competition area as it is laid for the Games, the Worlds and the Masters: a contest area of 10 m by 10 m in a safety area of 4 m, laid with tatami of 2 m by 1 m. budo.size (8 m to 10 m), budo.safety (3 m up), budo.areas (1 to 6, or { across, down }), budo.tatami (2x1, 1x1, 182x91), budo.platform, budo.officials (the technical table), budo.start (the tape) and budo.look choose what is drawn.

The tatami's colours are the IJF's yellow for the contest area and red for the safety area, which the rule does not say which is which; the other looks (yellow-blue, blue-grey, green-beige, green-red, black-red) are ours, not the rulebook's: the rule names only the two official colours and lets an organiser propose others. The AJJF's own guidebook shows a yellow contest area in a safety area of another colour and recommends the IJF's.

league: "ajjf" is the All Japan Judo Federation's layout, from its Tournament Management Guidebook 2023 (2-1, 2-3, 2-4): the tatami of 182 cm by 91 cm (the 200 by 100 cm of the IJF and the halves of both are also allowed), 5 or 6 cm thick; the red tatami of the danger zone, a tatami wide, inside the contest area, which the guidebook allows at events other than the Games, the Worlds and the Masters; and the red and the white tape 4 m (2 ken) apart. Mats of 91 cm do not divide 8 m or 3 m, so the sizes are made a whole number of mats: a contest area of 8.19 m in a safety area of 3.64 m.

import { budoPlan } from "@johnmorrisdotca/kyogijo-stadiums/budo";

const plan = budoPlan({ sport: "judo", budo: { areas: 2 } });
console.log(plan.judo?.contests.length, plan.judo?.gap, plan.box.x1, plan.box.y1);
// 2 4 32 18
const ajjf = budoPlan({ sport: "judo", league: "ajjf" });
console.log(ajjf.judo!.contests[0].x1 - ajjf.judo!.contests[0].x0, ajjf.judo!.danger);
// 8.19 0.91

Karate#

sport: "karate": the WKF's kumite area (wkf-kumite, the default) and its kata area (wkf-kata), from the Competition Rules of 2026 (Article 1).

The rules give no mat's size: 1 m by 1 m is drawn (ours, the size of a WKF-approved mat). The blue, the red and the dark blue of the looks are ours.

Kendo#

sport: "kendo": the shiai-jo of the International Kendo Federation's Regulations of Kendo Shiai and Shinpan (Article 2, the Subsidiary Rules' Article 1 and Figure 1): a wooden floor, square or rectangular, of 9 m to 11 m a side including the width of the line; the lines 5 cm to 10 cm wide and white; the cross at the centre 30 cm to 40 cm; the two kaishi-sen each 50 cm long and 1.4 m from the centre; 1.5 m kept clear outside. budo.size is the side (10 m by default, the middle: ours).

Sumo#

sport: "sumo": the dohyō. The clay square is 6.7 m a side and 34 cm to 60 cm high (the Sumo Rules, Dohyō Regulations, Article 1); the ring is 4.55 m across, made of 20 tawara: 4 tokudawara and 4 between each of them (the Association's Quiz No. 355); the two shikiri-sen are 90 cm long, 6 cm wide and 70 cm apart (Quiz No. 1091). The tassels of the roof are in the colours of the four quarters: green east, red south, white west, black north (budo.tassels). The width of a tawara, how far a tokudawara stands out, the width of the jano-me and the height drawn (55 cm) are ours: no rule gives them. budo.height sets the height, which the 3D view raises.

Kyūdō#

sport: "kyudo": the kyūdōjō, kinteki (28 m, league: "kinteki") or enteki (60 m, league: "enteki"): the shajō, the hall the archers shoot from, with the shooting positions (射位) and the honza (本座), the yamichi (矢道), the open ground to the azuchi (安土), the mound the targets stand against, and the path for fetching the arrows.

budo.shooters (1 to 12), budo.targets and budo.roof choose what is drawn. The width of the yamichi, the path and the azuchi are ours.

The dojo builder#

dojo(spec) lays a floor of tatami as real units and returns it as data; drawDojo(spec) draws it; drawKyogijo({ sport: "dojo", dojo: spec }) is the same drawing.

import { dojo, fourCorners } from "@johnmorrisdotca/kyogijo-stadiums/budo";

const hall = dojo({ jo: 20 });
console.log(hall.jo, hall.width.toFixed(2), hall.length.toFixed(2), hall.counts.full, hall.counts.half, fourCorners(hall.mats));
// 20 7.28 4.55 18 4 0
const small = dojo({ mats: [3, 2], pattern: "checker", kamiza: "east" });
console.log(small.jo, small.width.toFixed(2), small.length.toFixed(2), small.kamiza);
// 6 3.64 2.73 east

mats is the floor: a number is its area in jō (畳), and 8, 12, 20, 50, 100 and 200 give the usual shapes (a mat's width is the unit: 8 jō is 4 by 4 of them, 3.64 m square); [across, along] is the whole mats across and along; { width, length, unit } a size in m, ft, mat or jo. standard (or league) is the mat: chukyoma (1820 by 910 mm, the default), kyoma (1910 by 955), edoma (1760 by 880), danchima (1700 by 850) or judo-2x1; the sizes are those of the regions (English and Japanese Wikipedia).

kamiza (north by default) is the wall of the seat of honour (上座); shinzen puts the shrine (神前) there; entrances and windows (a list, or a number spread along the long walls) cut the walls; walls: false leaves the floor alone; areas lays judo contest areas of 8 m on the floor (it must fit); colours and look (green-beige, yellow-red, yellow-blue, blue-grey, black-red, green-red) paint it.

Blocks of contest areas, a room with a history and the weave of the mats#

• areas: { across: 2, down: 2 } lays a block of contest areas (four here) on the floor; areaSize (8 m to 10 m) sets their side; outline: true puts a band one mat wide in the third colour round each area, as the border mats of a floor of one colour do.
• surround is the wood between the mats and the walls, in metres; dais: true raises the seat of honour's platform at the middle of the kamiza wall; banner: true hangs a plain dark vertical banner there (a band, never an emblem); balcony is the spectators' gallery that dojoRoom() reports (crowd draws the stands).
• eras is the floor's history, oldest first: each era has a name, the from and to years (null where no source gives them) and any of look, colours, pattern, areas, areaSize and outline it changes. era: "earlier" picks one by name, year: 1990 the first whose years hold it, and with neither the last is drawn. colours (mat, alt, border, heri, floor, wall) are CSS colours. The looks yellow-green (pale yellow contest areas on green mats) and green-orange (green mats with red-orange border mats) are the dojo's own.
• texture: "weave" (judo and the dojo; the traditional lay has it by default, "none" turns it off) draws the rice-straw weave as fine ridges along each mat's long side, turned a quarter where a mat lies across, with a faint light edge on each mat. It is one repeating gradient, shared by every mat, works in every look, and drops away at the simple detail.

A dojo's crowd is its gallery#

crowd: true on a dojo draws its gallery, not a stadium: one thin band of 4 rows of plain brown seats behind a rail, set right against the walls just beyond the wood surround, with a few neutral people (a share of 0.4 taken unless density says otherwise) and no home or visitors, no card display, tunnel or benches. It comes from the same balcony data as dojoRoom() (balcony: { depth, rows, height }; balcony: false asks for the sport's own stands instead), so the 2D drawing and a 3D view agree; dojoGallery(options) returns those figures. The Nippon Budokan and the Ryōgoku Kokugikan are arenas and keep their full bowls (crowdStands() reports gallery: true only for a gallery).

The room as data#

dojoRoom(options) (in /budo) gives the room round a surface as plain data, in metres from the top left of the surface's box, for a 3D view to raise: the walls (centre line, thickness, height), the wood surround, the platforms (the dais with its height and footprint, the dohyō at its height), the banners (footprint, bottom and top heights), the balconies (the strip they cover, the height of their front edge, rows, the depth and rise of a row, the rail), the doors and windows (footprint, sill and head), the shrine, the Budokan's octagon (hall) and the mats (their thickness: 5 cm for the IJF's tatami, 6 cm for the AJJF's, whose rounded edge shows at the outer edge of the safety area). Every height that no source gives is ours, and notes says which; basis on a figure is source, plan or ours.

import { dojoRoom } from "@johnmorrisdotca/kyogijo-stadiums/budo";

const room = dojoRoom({ sport: "dojo", dojo: { jo: 20, dais: true, banner: true } });
console.log(room?.walls.length, room?.platforms[0]?.height, room?.banners.length);
// 4 0.3 1

Famous halls on the atlas#

The atlas has five halls (kind: "hall"), each with only what a source gives, and for each surface it offers a note of what is documented and what is only plausible (basis: documented, count or generic). A floor whose size no source gives is drawn at a plausible size and says so.

import { hallSurfaces, placeById, surfaceOf, surfacesOf } from "@johnmorrisdotca/kyogijo-stadiums/atlas";
import { drawKyogijo } from "@johnmorrisdotca/kyogijo-stadiums";

const kodokan = placeById("kodokan")!;
console.log(hallSurfaces(kodokan).map((surface) => `${surface.id} ${surface.mats}`).join(", "));
// main-dojo 420, main-dojo-earlier 420, school-dojo 240, international-dojo 192, womens-dojo 240, boys-dojo 114
console.log(JSON.stringify(hallSurfaces(kodokan)[0].options.dojo?.eras?.map((era) => era.name)), drawKyogijo({ ...surfacesOf(placeById("nippon-budokan")!)[0], style: "none" }).startsWith("<svg"));
// ["earlier","current"] true

The Budokan's floor is budo.hall: "budokan": the octagon (55 m across the flats, from the Budokan's leaflet) under the competition area, which must fit inside it; with crowd: true the stands close in round it.

The score#

A score draws a board on the surface with the teams (the sides) named on it. Team.budo (BudoScore) says what each side scored, as the sport counts it, and the board shows it:

A score of your own wins over the total worked out. Kyūdō and the dojo take the usual strip.

import { drawKyogijo } from "@johnmorrisdotca/kyogijo-stadiums";
import { KIMARITE_COUNT, kimariteName } from "@johnmorrisdotca/kyogijo-stadiums/budo";

const svg = drawKyogijo({
  sport: "judo",
  away: { name: "Blue", budo: { wazaari: 1, yuko: 2, shido: 1 } },
  home: { name: "White", budo: { wazaari: 1 } },
  status: "final",
});
console.log(svg.includes("ky-scoreboard"), KIMARITE_COUNT, kimariteName("yorikiri", "ja"));
// true 82 寄り切り

In 3D, in the stands and in the pageant#

• 3D. The dohyō stands up as its mound (budo.height, 55 cm by default; the rule gives 34 cm to 60 cm); the azuchi rises behind the targets of a kyūdōjō, each tilted back 5 degrees; a dojo has its walls (3 m, ours). A judo, karate or kendo surface lies flat: a platform's height is not in the rules.
• The stands. Judo, karate and kendo have an arena's bowl, closer round the Budokan's octagon (budo.hall); sumo the hall of the Kokugikan: box seats and a gallery; a kyūdōjō and a dojo a gallery along the sides. The profiles are ours: no rule gives the stands.
• The pageant. A carpet or a stage lies over each half of a surface, and the emblem in the middle; for a dohyō it lies in the ring, for a competition area in its middle.
• Ranges and zones. range crops to the contest area, the start, the ring, the shajō, the yamichi, the azuchi, the kamiza end or a half; the zone set budo-areas is the surface in its areas.

Edit this page on GitHub