Tanner was once very prominent in the Dueling world, working his way up to facing Jack Atlas himself in a Turbo Duel. However, Jack easily defeated him, and from then on Tanner was little more than a joke in the Dueling world. Distraught, he fell in with criminals, drunks, and underground Duelists, and was quickly arrested. (In the dub, his alcoholism and drug problems are only implied as Tanner states "It was all downhill from there", indicating it was after his loss to Jack.)
At the Facility, he is highly respected. He has all the new inmates Duel him in order to see if they are also worthy of respect.
He meets Yusei Fudo after Yusei is transported to the Facility. Tanner challenges Yusei, who is unable to Duel, since he doesn't have a Deck. Yanagi Duels in place of Yusei. Tanner brings out "Giant Ushi Oni" on his second turn and uses it to turn Yanagi's strategy against him, defeating him that same turn.
Tanner speaks ill of Tenzen Yanagi's cards and stomps on them causing Yusei Fudo to challenge him to a Duel, where Yusei uses Yanagi's Deck. Yusei defeats him with some difficulty and afterwards Tanner becomes friends with Yusei.
Yusei intends to escape the Facility with Tanner and Yanagi. Tanner gets beaten up and harassed by Mr. Armstrong for being friends with Yusei. (In both versions, there's a more elaborate reason why. In the original Japanese version, Armstrong searches Tanner's cell for an alleged 'hidden weapon', using a palmed switchblade to 'find' it in Tanner's vest, while in the dub, Armstrong beat him up because he had smuggled magazines in his cell though Yusei insists Tanner had none, suggesting Armstrong was greatly unfair.)
After Yusei won the Duel with Armstrong, Tanner gave Yusei his "Giant Ushi Oni" as partly as a parting gift and partly as a lead to Blister, a friend of Tanner who could help Yusei.
He and Yanagi are released from prison due to their companionship with Yusei. They go to meet with Yusei and Blister. Tanner becomes suspicious of Yusei being invited to the Fortune Cup, positive the tournament is an elaborate trap. Throughout the tournament he supports Yusei, watching from the sidelines. After Yusei wins the Fortune Cup, he helps Yusei escape from the reporters.
After safely reaching Blister's hideout, Yusei tells Tanner and the others about the mysterious spider mark vision shown by the Crimson Dragon. When Yusei says he wants to meet Rex, Tanner objects but is cast aside by Yusei. He then moves into Leo and Luna's apartment. He arranged for a meeting with Sayer in hopes of gaining the support of Akiza Izinski but is tricked by Sayer and they are knocked out by gas. Yanagi and Tanner are taken to a secure room and locked inside.
Yanagi and Tanner wake up in the room wondering what happened. They figure out that Sayer put them there and he could not be trusted. They try busting the door for a bit but get nowhere. The entire building shakes and the building starts collapsing. The door is finally loose enough to ram and they bust the door. They find Luna watching her brother through glass. Tanner breaks the glass and frees Leo. They try to find a way out but Luna is lead to Akiza Dueling. They follow and watch Akiza and Misty Duel. The Duel stops when the building collapses and Tanner, Yanagi, Leo, and Luna run out of the building. They meet Jack outside and tell him that Akiza is inside and may need help. They run and the building collapses. They find out that Akiza is in the hospital and they visit her. Bolt, and Yanagi, are last seen seeing the Signers off to the Satellite.
Tanner uses a Beatdown Deck, focusing on the otherwise-mundane card "Ushi Oni". With "Cost Down", he can bring out "Ushi Oni" in one turn, and on the next he can Tribute it for his ace card, "Giant Ushi Oni".