A heya (部屋, literally 'room') is a sumo stable — the training community where professional wrestlers live, eat, and train together under the guidance of a oyakata (stable master), who is typically a retired sumo wrestler who has purchased the right to operate a stable.
The heya system is the backbone of professional sumo. Wrestlers join a stable as teenagers and the heya becomes their home and family. The stable master is legally responsible for the wrestlers' conduct, training, and welfare. All wrestlers from the same stable share a dormitory, train on the same practice ring (also called dohyo), and eat together — consuming enormous quantities of chankonabe, the traditional sumo stew.
The daily routine in a heya is rigorous: practice begins at dawn (around 5-6am) and lasts several hours, followed by a large communal meal and a long nap to encourage weight gain. Higher-ranked wrestlers practice last and eat first — the strict hierarchy permeates every aspect of stable life.
Currently, there are approximately 44 active heya in Japan, ranging from powerhouses like Miyagino (Hakuho's former stable, now Isegahama) with dozens of wrestlers, to smaller stables with just a handful. Each stable's identity is closely tied to its master's style and lineage.