Yami Yugi and Mokuba Kaiba's Duel

Yami Yugi and Mako's Duel was a Duel between Yami Yugi and Mokuba Kaiba in the Duelist Kingdom tournament.

Prior events
While Maximillion Pegasus tried taking over KaibaCorp, Mokuba swallowed an important key, so Pegasus had him kidnapped until the key could be retrieved. Mokuba was brought to Pegasus Castle on the Duelist Kingdom island. However Mokuba escaped the castle.

Mokuba knew that Pegasus' plan involved defeating Yugi Muto in the finals of the Duelist Kingdom tournament, so Mokuba tried to eliminate Yugi from the tournament before that could happen. He stole a Deck and five Star Chips form one of the participants and planned to use them to defeat Yugi.

Yami Yugi, Joey Wheeler and their friends saw the boy, whom Mokuba had stolen from, being restrained by Kemo and told he was to be sent off the island for losing all his Star Chips. The boy explained that the Star Chips had been stolen, but Kemo was unsympathetic. Joey offered to catch the thief and asked that Kemo not remove the boy from the island until then. Joey then added that he would keep half the Star Chips as a reward.

While searching for the thief, Yami and Joey saw the boat eliminated participants leaving the island and among them was the boy whose Star Chips had been stolen, meaning they wouldn't be able to return the Star Chips to him. Mokuba masked with a bandanna appeared before Yami Yugi and his friends. They recognized the person before them as the thief, but didn't immediately recognize that he was Mokuba.

Yami accepted Mokuba's Duel request, despite knowing he was the thief. The two of them wagered their five Star Chips. As they lay down their Star Chips, Yami noticed that Mokuba didn't have a Duel Glove, meaning he wasn't invited to the tournament. He wondered if the thief stole the Star Chips just to challenge him and started to become suspicious of something. Meanwhile, Yami's friends wondered why he accepted the Duel, when his opponent was clearly the thief.

The Duel
Mokuba Summoned "Man-Eating Plant" (ATK: 800).
 * Mokuba's turn

Yami Summoned "Winged Dragon, Guardian of the Fortress" (ATK: 1400).
 * Yami's turn

"Winged Dragon, Guardian of the Fortress" attacked and destroyed "Man-Eating Plant" (Mokuba: 2000 → 1400 Life Points).

Mokuba Summoned "Krokodilus".
 * Mokuba's turn

Yami Summoned "Celtic Guardian" (ATK: 1400).
 * Yami's turn

"Celtic Guardian" attacked and destroyed "Krokodilus" (Mokuba: 1400 → 1100 Life Points).

Joey thought that the thief wasn't very good and Téa agreed that he was no match for Yami Yugi. Yami advised Mokuba to give up, as the game is not so simple that it can be won with stolen cards. Mokuba knew he didn't have a chance of winning, so he made a grab for the Star Chips, but Yami caught him by the wrist, before he could escape. Yami then removed Mokuba's cap and bandanna, revealing his identity.