Sumo wrestling is a centuries-old tradition that has its roots in the Shinto religion. Its top wrestlers hold God-like status. All aspiring wrestlers must first be recruited by a stable, where professional sumos eat, sleep and train. However, life inside a stable is shrouded in secrecy. Reporter Sahar Zand heads to Japan to examine the darker side of sumo, from health issues to claims of bullying and concerns of head injuries.