Sakyo is the owner and leader of Team Toguro in the Dark Tournament. He is a very rich man, having gained his wealth from gambling all his life. He is usually a very calm, collected, and intelligent person while keeping his evil side influencing his outside self. For both the Rescue Yukina arcs and Dark Tournament Saga, Sakyo made few appearances, but in truth was the real villain of both arcs, merely using Team Toguro as his own personal puppets, although it appears none of the characters realized this.

Sakyo was once one of five siblings, but unlike his siblings, he "veered from the norm". While his siblings became civil servants, he began to gain mental insanity and coveted blood. Over a three year period, he slowly moved from dissecting frogs and fish, to cats and dogs, and finally real humans. Soon he entered the gambling business, using a key strategy to help him win by threatening to wager his life. Most of the time the others quit when they saw he was serious, but this was suspected five times. He states one time was up against the Black Book Club, or BBC, which he was a former member of, and the last this was suggested, coincidentally the last time he wagered his life, was during the final rounds of the Dark Tournament. It is sometime in his gambling life he became a member of the BBC.

Sometime during his membership, former Spirit Detective Shinobu Sensui had witnessed an experiment the BBC were doing, Sakyo included. They had made several humans slaughter demons taken from a portal between the human and demon planes, and the humans then bathed in their blood. Angry, Sensui killed all of the humans, and began to question humanity.