Saruwatari worked for Kaiba Corporation as one of Seto and Mokuba Kaiba's private bodyguards, but he was actually working for Industrial Illusions the whole time, gathering information from within Kaiba Corporation and giving it to Maximillion J. Pegasus.
During Death-T, he and other guards held Katsuya Jonouchi and Anzu Mazaki at gunpoint, while Dark Yugi faced Seto Kaiba. However Hiroto Honda appeared and with Jonouchi proceeded to fight off the guards, who are then told to step down by Mokuba.
Saruwatari worked for Pegasus on Duelist Kingdom, while Seto Kaiba was missing. He apprehended Mokuba Kaiba after his Duel with Dark Yugi. Dark Yugi challenges him to a Duel for Mokuba's freedom. Since Saruwatari did not play games, he arranged for the Ventriloquist of the Dead to Duel Dark Yugi. Although Dark Yugi won, Saruwatari still took Mokuba back to Pegasus.
Later at Pegasus Castle, Saruwatari was confronted by Kaiba, whom he believed to be dead. He tried to stop Kaiba, after Kaiba held a gun to Croquet's head. Croquet panicked and ordered him to obey Kaiba. While Croquet was taken hostage, Kaiba demanded that Saruwatari get Pegasus. On Pegasus order, he gave Kaiba the five Star Chips that Mokuba had stolen to wager in a Duel against Yugi.
Sarutawari acted as the guard at the entrance to Pegasus Castle and attempts to stop Yugi and Jonouchi's friends from entering, as they were not Duelists. However Jonouchi knocked him unconscious and they all entered.
Saruwatari, still working for Industrial Illusions, tried to stop Jonouchi, Honda and Mokuba from advancing to the Kaiba Corporation building. However he was easily beaten in a fight by Jonouchi.