The Mawashi: The Belt a Sumo Bout Is Fought Over
Every new viewer notices it, and most decide it is a costume. It is closer to equipment. Half of what happens in a sumo bout is about getting hold of it, and the other half is about not letting anyone else.
The まわし (mawashi) is the belt worn in the ring. It is the only thing a wrestler wears while competing — no shoes, no protection, nothing else.
And that is not modesty or tradition dressed up as sport. It follows directly from how sumo is won.
Why the belt is the point
As the two ways to lose explains, you win by moving your opponent out of the ring or putting him on the clay. Both are questions of balance and leverage — and to apply leverage to a man wearing almost nothing, you need something to hold.
The mawashi is that something. It is the handle.
What it is made of
It is a long strip of heavy cloth, wound several times around the waist and between the legs, and knotted at the back of the body. It is pulled extremely tight, for the plainest of reasons: so that it does not come loose while a man of considerable weight is pulling on it.
A loose belt would be no use to either wrestler. It would slip out of the attacker's hand, and it would not stay on the man wearing it.
If a mawashi does come loose mid-bout, the referee stops the bout — he calls 待った (matta) — and ties it up again himself, there on the clay. The two wrestlers then resume. It is treated as something to be fixed, not laughed at.
Why the grip decides the style
Because the belt is the handle, wanting it or not wanting it splits the sport into the two approaches described in push or grapple.
四つ相撲(yotsu-zumo) — the belt style. Close the distance, take a grip, and work from it.押し相撲(oshi-zumo) — the pushing style. Keep the opponent at arm's length so that no grip is ever available.
The names of the techniques follow the same logic. Oshidashi and yorikiri are separated by whether the winner was holding on. Uwatenage and shitatenage are named for whether the throwing arm was the upper one or the lower one — over the opponent's arm, or under it.
Once you know that, a great deal of sumo vocabulary stops being a list to memorise and becomes a description of one object.
The one worn for ceremonies is different
What a 関取 (sekitori) wears for the ring-entering ceremony looks nothing like what he fights in. It is a different object with a different name: the 化粧まわし (kesho-mawashi), an embroidered apron, heavy and made to be looked at. The fighting one is plain and made to be pulled on.
This is the same idea that runs through the rest of the sport, and through the banzuke: rank is made visible. What a wrestler is allowed to wear, and when, is part of how far up he is.
The trap for new viewers
Do not read the colour as a team, a country or a rank. Within the fighting mawashi it is essentially personal, and it will not tell you anything about who is likely to win.
What to watch for
In the second after the charge, look at the hands rather than the faces. Watch whether either man gets a hand onto the belt, and where.
If both men are holding on, you are about to watch a slow contest of leverage. If neither is, you are about to watch a fast one of position. That single observation, made one second in, tells you what kind of bout you are about to see.
The two answers to the question this object poses, seen across a whole career.