There are six official tournaments each year. It runs 15 days and each wrestler will be in a match each day. The best record will win the tournament.
basho
A Japanese official Sumo Tournament is called 本場所 /hon ba sho/.
The sumo that I think is the is not in japan but somewhere and his name is Emanuel Yarbrough one of my favorite sumo wrestlers
The bout is called a match in sumo wrestling. It would occur during a tournament or basho.
To be in an official tournament, you must be a member of a recognized sumo stable. You also have to appear on the Banzuke.
Mount Fuji Sumo Wrestling Tournament
There are six official tournaments each year. Unless they are injured, they will participate in all six.
Banzuke is the record of professional sumo wrestlers listed by rank before an official tournament. The translation of banzuke is ranking list.
Japan does not have a national sport. The top three professional associations are Baseball, Association football and Sumo. The biggest participation and spectator sport is baseball followed by association football.
The most famous sumo wrestler in Japan is probably Hakuho Sho, a legendary rikishi from Mongolia. He holds the record for the most tournament championships, with 45 titles, and is widely regarded as one of the greatest sumo wrestlers of all time. Hakuho's dominance in the sport and his longevity have made him a prominent figure in both sumo and Japanese culture. His retirement in 2021 marked the end of an era in the sport.
In Japanese, there is no visible indication, it is determined by the context. He was a sumo wrestler. There were ten sumo in that stable.
What English-speakers think of when they say "sumo" (i.e. heavyset men wrestling) is also called "sumo" in Japanese. Basically, sumo is sumo!