Yama is a former professional sumo wrestler who fought from Onoe stable beginning in January, 2007 at the age of 22, and at his peak weight of 586 lbs. was the heaviest Japanese-born sumo wrestler in history. A graduate of Nihon University, he won several amateur championships at national, world, and university levels before turning professional, making the top makuuchi division by the January, 2009 tournament. He fought under the ring name Yamamotoyama, formed simply by adding the suffix "yama" (mountain) to his birth family name. Despite his meteoric rise through the ranks, he struggled with injury after reaching his highest rank of maegashira 9, and fell to the second-highest juryo division. He returned to makuuchi for a single tournament but then suffered further injuries, forcing his withdrawal from several tournaments and ultimately dropping down to the fourth-highest sandanme division. In April of 2011 he was implicated in a wide-reaching bout-fixing scandal. Although he maintained his innocence of any putative bout-fixing, he accepted the punishments handed out by the Japan Sumo Association and retired from professional sumo.

Besides his forays into acting and reality TV, he promotes the sport of sumo in the United States by staging training exercises and exhibition matches with other amateur sumo wrestlers.