There are currently 46 heya (stables) in sumo.
All bear the name of their stablemaster.
Every wrestler, referee, ring announcer, hairdresser, etc., belongs to a heya. The vast majority live in the building that houses that stable.
Some like Nishiiwa Beya have been around for just over a year.
Others like Dewanoumi Beya have existed for centuries.
Many stables have closed down over the years.
In all 129 different stable names have been used in sumo. Some heya have changed only their name. Others have used the same moniker as completely unconnected stables that existed in the past. Many historical stable names are no longer in use.
There are many reasons that heya close down. Sometimes a stablemaster passes away without a clear successor. Occasionally recruiting dries up to the point where there are only a few rikishi left and the stable merges with another. In rare cases, the Japan Sumo Association has shut down heya either temporarily or permanently for an infraction.
Rikishi from closed stables normally either choose to retire or move to another heya.
While there is no “free agency” in sumo, there have been times when wrestlers from a stable about to close down have been allowed to chose different heya.
A move to a new stable can come with a new name as well. Wakamisho, who had the Wakami prefix common to Magaki Beya wrestlers, became Terunofuji after moving to Isegahama Stable using that stable’s traditional Teru.
What happens to the buildings of closed heya?
Some become chanko restaurants, others get razed and have apartment blocks put up in their stead.
Stables closing and rikishi moving to a new heya is more common than many imagine.
In fact there are over 40 wrestlers in sumo right now that are members of a different stable than the one they initially joined when starting out.