The Meikyû Brothers were hired by Maximillion J. Pegasus to work as Player Killers in his Duelist Kingdom tournament. The two Dueled as a team, with their "Labyrinth Wall" card enabling them to change the playing field to resemble a complicated underground labyrinth. The two guard an underground area of the island. It is here that they met Yugi Mutou and Katsuya Jonouchi, who needed to defeat the brothers in order to pass and move on to Pegasus Castle. They began a Tag Duel, in which the brothers had a cohesive strategy, with their Decks built to play off of each other. In addition to changing the gameplay, the brothers' Decks focused on the Summoning of their powerful "Gate Guardian" monster, by gathering its component pieces onto the field.
Although they came close to victory, the brothers were defeated when Dark Yugi and Jonouchi's "Black Skull Dragon", powered by "Copycat" mimicking the brothers "Ryoku", defeated their "Gate Guardian". With their victory, Yugi and Jonouchi obtained enough Star Chips to qualify for the tournament's final rounds. However, the brothers had another test that Yugi and Jonouchi needed to pass. They informed them that one of two doors was the true exit. The brothers claim that from then on, one of them would speak only lies, while the other would speak only the truth. Dark Yugi realized that both brothers were lying and tricked into admitting this via the use of a two-headed coin. He and Jonouchi were then able to move on.
