The Roof Above the Ring
There is a roof over the ring. Nothing holds it up — it hangs. From its four corners hang four tassels, and each one is a colour, a season, a direction and a guardian. It is the part of the building a broadcast never shows you properly.
The structure is called 吊り屋根 (tsuriyane) — a "hanging roof". It is suspended above the dohyo, and it is put in place before each tournament rather than being part of the building.
The four tassels
At each corner hangs a large tassel, 房 (fusa). There are four, and they are four different colours. The Association sets out what each one means.
| Tassel | Season | Direction | Guardian |
|---|---|---|---|
| 青房 blue-green | spring | east | 青龍神 blue dragon |
| 赤房 red | summer | south | 朱雀神 vermilion bird |
| 白房 white | autumn | west | 白虎神 white tiger |
| 黒房 black | winter | north | 玄武神 black tortoise |
The Association describes these four as guarding the safety of the ring.
What that arrangement is doing
Read the table down rather than across and the design becomes clear.
Four corners carry the four seasons and the four compass directions. Together they cover a whole year and a whole horizon — and they are pointed at one small circle of clay, about four and a half metres across.
That is the same instinct as everything else in why sumo looks like a ceremony: the sport keeps arranging the world around the ring rather than treating the ring as a piece of sports equipment.
The Association publishes a photograph of the roof being installed before a tournament, and the point of the picture is scale: a single tassel is a large object, handled by people. A television camera flattens all of that, which is why the roof reads as a backdrop on screen and as a structure in the room.
The tassels replaced four pillars
The roof has not always hung. Until 1952 it stood on four wooden pillars, one at each corner of the ring, and a judge sat at the foot of each of them.
In September of that year the pillars were taken out and the roof was hung from above instead. The reason was the audience: a pillar at each corner blocked the view from a quarter of the hall. Television arrived the following year, and found a ring it could shoot from any angle.
The tassels date from exactly that moment. Each pillar had been wrapped in cloth of one of the four colours; when the pillars went, the colours were kept and hung from the corners of the roof instead. So what you are looking at is the last surviving piece of a structure that no longer exists.
It is not part of the building
This is easy to miss. The roof is installed before a tournament and taken down afterwards.
So it is not architecture. It is equipment — like the clay of the ring itself, which is built for each tournament and removed again. The venue is a venue; the roof and the ring are brought to it.
That also explains its size. Photographs of it being installed show a single tassel is large enough to be handled by people, which is not the impression a television picture gives.
The trap for new viewers
On a broadcast the roof reads as decoration hanging in the background, partly because cameras crop it and partly because the tassels look small at that distance. It is a substantial object suspended over the men competing, and if you attend, it is the first thing worth looking at — as suggested in going to a basho.
The colours you will actually see
One practical note. The Association writes the blue tassel as blue with green in brackets, and in the hall it reads as a deep green rather than the blue you might expect.
So if you are counting colours and find green, white, black and red rather than blue, white, black and red, you have found all four. Nothing is missing.
What to watch for
The next time a bout ends near the edge, watch the wide shot rather than the replay.
You will catch the corner of the roof and one tassel at the top of the frame. Once you know it is a season and a direction and a guardian rather than a curtain, that corner of the picture stops being empty.
Why there is a roof over a sports ring at all.
Source: Japan Sumo Association, 大相撲クイズ No.7 (the four tassels, their seasons, directions and guardians), retrieved 8 September 2026. The English names of the four guardians are our own renderings.