Yu-Gi-Oh! 5D's episode 71: "French Twist, Part 1"
Boss is the supervisor from the Riding Duel Business Group.
Boss is the one who schemes to have Yusei Fudo kidnapped. After Yusei wakes up, Boss tells him he is from the Tour Riding Group. Yusei is puzzled at why such an organization would do that. However, Boss tells him what those who really do not know this group assume.
When Yusei asks him why he was abducted, Boss reveals to him the reason, along with his devious methods to make it happen. Knowing that Yusei is the winner of the Fortune Cup, Boss intends to recruit him into his team for the World Racing Grand Prix. Yusei declines, stating that he already plans to enter in with his long time friends, Jack Atlas and Crow Hogan.
Boss clarifies that he doesn't care, assuming that no matter what, Yusei will join them. He reveals that they will even use their doctor's psychology on Yusei so that he can achieve these goals. When Yusei replies that that sort of thing wouldn't be allowed, Boss abruptly states that it will, for only them and him know about this and no one else.
His plans are later foiled by Akiza Izinski and Mina Simington, as the two of them are able to find the truck containing Yusei through the use of the Mark of the Dragon. However, after Akiza opens the sealed up door with her "Rose Tentacles", he orders his employees to make the truck go faster in order to destroy Yusei's Duel Runner.
Despite this, Yusei and Akiza are able to escape from the truck that fell off the road and into the ocean with the help of his Duel Runner.
He later reappears at the climax of Yusei and Sherry's duel in an attempt to crush them under another truck. His plan is once again foiled by Akiza, who once again uses her psychic powers. Once she materializes Yusei's "Stardust Dragon", the "Dragon" itself uses its body to momentarily stop the truck while they pass.
Upon seeing this, Boss and his thugs try to leave but are stopped by Sherry's guardian, Elsworth, who beats them all up.