A rikishi is a professional wrestler in the sport of sumo, which is a traditional Japanese form of wrestling. Rikishi compete in a circular ring called a dohyo, where they aim to force their opponent out of the ring or make them touch the ground with any part of their body other than the soles of their feet. Rikishi come from various backgrounds and undergo rigorous training to develop strength, technique, and discipline. They live in training stables known as heya, where they follow strict routines and adhere to a specific lifestyle, including a unique diet that helps them gain weight and build muscle.