In the Duelist Kingdom tournament, Bonz, Sid and Zygor met Bandit Keith, who agreed to coach them through the tournament, so all four of them would advance to Pegasus Castle. Keith wanted revenge against Maximillion Pegasus for humiliating him in the final match of the Intercontinental Championship. While helping them win Duels the first day of the tournament, Keith secretly intends to use them for their Star Chips. When Keith finds out about Yugi Muto, Joey Wheeler, and the rest of the gang, he plans to get in their way and eliminate them.
There are two parts of the quest chain for each continent. The first part involves defeating numerous Master Pet Tamers, and the second requires you to triumph over the Grand Master Tamer. After you've bested the Grand Master Tamer, dailies from each Tamer will unlock for that continent. All the dailies continue to reward experience for your companions, however only the Grand Master daily quest will reward the Sack of Pet Supplies.