Mongolian sumo wrestler appointed grand champion
"Mongolians do so well because their national wrestling style, Bokh, is very similar," Rob Ó Néill, president of the British Sumo Federation, told the BBC.
In Bokh, fighters rely on leg sweeps, which are legal in sumo but were uncommon until the wave of Mongolian fighters turned professional.
"It was like a kickboxer fighting a boxer," Mr Ó Néill said.
Although the Japanese fighters have improved at defending these moves, they are a fundamental part of the Mongolian fighting philosophy in a way they are not in Japan.
Sumo is a highly traditional sport that takes time to adjust.
Another reason behind the success of the Mongolians is that they start wrestling from a very young age.
"They're also absolutely huge guys," Mr Ó Néill added.
Unlike other combat sports, professional sumo does not have weight categories.
To be a professional, fighters must eat, sleep and train with one another in a type of training hall called a stable.
There are currently around 40 stables officially recognised by the Japan Sumo Association.
"It's their entire way of life from when they join to when they retire," Rob said.
Restaurants serving chanko, a type of stew eaten in vast quantities by the wrestlers, are often opened by former fighters near stables.
Each is only allowed to train one foreign wrestler, and as Japan is the only country with professional sumo, the majority of fighters are homegrown.
The winner of the men's amateur Sumo World Championships, which fields competitors from almost 90 countries, is invited to join a stable.
