A prominent sumo coach and three wrestlers have been charged with beating to death a teenage apprentice in an attack that shocked Japan.
Mr Yamamoto has repeatedly denied the allegations he faces
Junichi Yamamoto, known as Tokitsukaze, and the wrestlers are accused of beating Takashi Saito as a punishment for trying to run away.
The 17-year-old collapsed and later died in hospital.
Prosecutors in Nagoya city have charged the men with causing injury resulting in death. All four deny the charges.
The authorities say Mr Saito died of multiple traumatic shock after being beaten with baseball bats.
The four men are said to have subjected him to excessive sparring sessions on 25 and 26 June before a tournament in Nagoya.
WHAT IS SUMO?
Sumo is Japan's national sport, dating back hundreds of years
Two wrestlers face off in an elevated circular ring
They try to push each other to the ground or out of the ring
Wrestlers are ranked, and the highest level is yokozuna
The death plunged the sport into crisis last year, and Prime Minister Yasuo Fukuda recently called on the sumo authorities to ensure such incidents could not happen again.
Sumo wrestling is Japan's national sport and those involved are widely seen as role models, and much respected for their honour and humility.
Young sumo wrestlers train in tightly-knit "stables" where they eat, sleep and practise together and are sometimes subjected to harsh treatment in the belief that it will toughen them up.