Yokozuna is the highest rank in sumo.
To date just 72 men have attained the status since it was first created in the late 1700s.
Yokozuna can never be demoted. They are seen as the living embodiment of sumo, and when no longer able to uphold the standards of the rank, they are expected to retire.
In recent decades, promotion to yokozuna requires two consecutive championships (or the equivalent record) while at the rank of ozeki.
Currently there are three yokozuna — Kisenosato, Kakuryu and Hakuho.
Hakuho, who has dominated sumo for over a decade, is considered to be among the greatest champions of all time and holds most of the sport's significant records.
Every day during tournaments all yokozuna perform a ring-entering ceremony with two other wrestlers as attendants. They are known as the "dew sweeper" and "sword bearer."
Yokozuna literally means "horizontal rope" and the name comes from the Shinto-style white rope they wear around their waist.
There are two type of knots at the back of the rope and two corresponding styles of ring-entering ceremony.
Those with a double-looped knot perform the Shiranui style. Both arms are stretched out and it is considered an attacking style.
Men with a single-looped rope use the Unryu style, which contains both offensive and defensive elements.
Traditionally, Shiranui was less common and considered unlucky as several yokozuna using it had less than stellar careers.
That was of course before Hakuho adopted the style upon promotion. With the veteran champion closing in on his 41st Emperor's Cup, any superstitions around the Shiranui style have been laid to rest.
Unlike with other wrestlers you won't be able to see yokozuna walking in and out of Ryogoku Kokugikan. Among their many perks is a parking spot underneath the arena.