The Big Five

The Big Five are a group of five fictional businessmen that appear in the anime series Yu-Gi-Oh!. Kaiba Corporation

Initially known at the Board of Directors for Kaiba Corporation, the Big Five work for Gozaburo Kaiba, producing weapons of mass destruction. When Gozaburo's step-son Seto decides to make his play for power, he convinces the Big Five he'll restore them to their former power and claims that Gozaburo does not give them the respect or power they deserve. The Big Five agree, and thus buy 49% of Kaiba Corporation. Combined with 2% that Gozaburo had previously given to Seto for a test to prove his business skill, the Big Five vote out Gozaburo and vote in Seto as the president of the company.

However, Seto quickly backs out on their deal, stripping them of their power and leaving the Big Five little more than figureheads and consultants. Furious over their betrayal, the Big Five strike a deal with Maximillion Pegasus, similar to their previous deal with Seto: if Pegasus defeats Seto and Yugi Mutou in duels, then they will use their 49% to vote Pegasus into power of the company by kidnapping Seto's brother Mokuba, who has been entrusted with the security codes to the two percent the Big Five need.

The plan fails, and when Seto learns of their betrayal he threatens to fire them. The Big Five offer Seto his complete Virtual Reality game as a peace offering, sparking the Legendary Heroes arc. After being rescued, what Seto did to the Big Five is not known. Presumably their minds were trapped in the Virtual World as they had intended to do to Seto, as this sets the stage for their next appearance.

Virtual World
The Big Five wander Kaiba Corporation's computer banks for some time until they are found by Gozaburo's biological son Noah. Noah also desires to take control of Kaiba Corporation from Seto, and the two strike a deal. Noah lures Seto, Yugi and his friends to an underground military base, and there forces them to enter his version of the Virtual World. The Big Five greet them and reveal the deal they have made with Noah: after being trapped in the Virtual World, they have lost their connection to their bodies and thus need new ones. In exchange for being allowed access to the bodies of Seto, Yugi and his friends, the Big Five will defeat each of them in a duel.

One by one the Big Five fail to defeat their chosen opponents, and Noah is furious. As a last ditch effort, the Big Five use the body of Tristan Taylor to unite into one and duel Yugi and Joey Wheeler in a two-on-one match. They once again fail to defeat them, and are summoned back to Noah's headquarters. Noah refuses to give them a third chance, and as punishment seals each of the Big Five in an isolated portion of the Virtual World. Following this they are never seen again and are presumably deleted when the fortress the Virtual World is stationed in explodes.