Nistro

Gauche is a character appearing in the Yu-Gi-Oh! ZEXAL anime. He is Dr. Faker's left-hand man and a committee member responsible for maintaining the World Duel Carnival along with Droite. Ultimately, his and Droite's true task during this tournament is searching for "Number" cards but he is more concerned with defeating Yuma Tsukumo and the Original Number before Kite does.

Appearance
Gauche has flame-shaped dark red hair with a lighter red fringe and purple eyes. He has a Duel Disk which looks a lot like IV's, but more of a fireball based design. He also has a Duel Gazer red tatoo, like Kite Tenjo, III, IV, V, and his partner Droite.

Also prior of entering the WDC as another participant, Gauche used a black and dark red trench coat with a high collar over a red shirt with dark red trousers black shoes and black gloves as well as a bracelet on his left wrist identical to the one on Droite's right ankle. Later, he can be seen wearing a grey and black colored coat with orange ruffles as well as two belts and leather pants with white and brown cowboy boots.

Personality
Opposite to Droite's cold-blooded personality, Gauche is a very high-spirited person evident to how excited he got during the opening ceremonies of the World Duel Carnival. He also has a habit of saying "nori" in each of his sentence.

He also seems to take his job less seriously as when investigating mysterious Duels within the tournament, he joked about how some of the Duelists were defeated whilst Droite maintained a calm manner whilst investigating. This tends to cause frequent arguing with his partner, but they actually get along better than they initially appear and their dueling styles complement each other well. It also seems Gauche values Droite (or at least his co-workers in general) highly, as during their duel with Yuma Tsukumo, he activated a card that served no other purpose than to take the hit for Droite.

Gauche seems to love Dueling, punishing heavily anyone that dishonors Dueling. As a member of the committee, he is very severe when punishing a cheater, to the point of physically injuring the participant or forbidding him/her of Dueling in the Heartland City for the rest of his/her life.

Gauche can be quite competitive with Kite Tenjo, having some form of rivalry with him in collecting "Numbers". After his defeat, he formed a friendly rivalry with Yuma because he likes his spirit, but he also considers Yuma as his "prey" since he possess the "Original Number".

Etymology
Gauche" means "left" in French. This may be a reference to the fact of him being Dr. Faker's "left hand" while Droite is the "right hand".

World Duel Carnival Preliminaries
During the opening ceremonies of the World Duel Carnival, Gauche along with Droite and Mr. Heartland kept watch over various parts of Heartland. Seeing the amount of Duelists excited Gauche, but he was quickly scolded by Droite who told him to be more professional. He then argues with Droite but is stopped by Mr. Heartland. Kite Tenjo arrived, with Gauche joking about how quickly Kite responded to Heartland's summons. Kite gave him an annoyed look in response.

Gauche and Droite investigated incidents during the World Duel Carnival, such as Housaku Yasai's Vegetable Death Matches. During that time, he wore a blue Duel Gazer. They are responsible for eliminating Duelists who break the rules of the tournament, now Dueling with a tattoo-like Duel Gazer akin to Kite's. When Flip does so, Yuma Tsukumo intervened and Dueled them in Flip's place.

Their combination overpowered Yuma and drastically lowered his Life Points. On an attempt to turn the Duel around Yuma manages to Summon "Utopia", surprising Gauche and his partner as he holds a "Number" card. When Droite Summons "Photon Papilloperative", Yuma identifies them as being affiliated with Kite, and they learn that he has Dueled Kite. Yuma gave up hope when they reduced him 100 Life Points, but Astral returned and was briefly visible to everyone watching the Duel. Droite and Gauche identified him (Astral) as the "original Number". Astral helped Yuma execute a winning move and Yuma attacked Droite. Gauche defended her with "Bouncer Guard", resulting in him losing instead of her. After the Duel, Gauche asks Droite not to tell Mr. Heartland about Yuma because he wants to defeat him himself before Kite does.

After Hart Tenjo disappears from Heartland Tower, Gauche and Droite went to look for him via a helicopter. After finding him, Gauche blamed Yuma for kidnapping him and when he tries to take Hart back, he created a powerful energy to force Droite and Gauche to retreat, when they return, Hart, Yuma and Tori have disappeared.

Having found that Hart has disappeared, Kite contacted Gauche and Droite in order to find out what has happened. Gauche thought it would be best to ignore Kite, but Droite listened to what he had to say, and then told him the area of the city where Hart was last seen. After Hart was abducted by V, Gauche and Droite manage to find Yuma in order to question him on Hart's whereabouts. Unfortunately for Gauche, Yuma kicked him in the crotch in order to escape, causing him immense pain. He then regained his power and goes to attack Yuma again, but is stopped by Kite. After discussing about what to do, he along with Droite decided to leave the job to Yuma and Kite. They then got back into their helicopter and fly away.

After Kite and Yuma defeated IV and III, Hart was rushed to the hospital as he required medical care. Angered at how Mr. Heartland didn't prevent Hart from being hurt, Kite attempted to talk to him about the matter, but is stopped by Gauche and Droite as he was having a meeting with Dr. Faker about the situation at hand. Gauche mocked Kite for joining up with Yuma, and questions him on why he didn't reveal Yuma's identity to Mr. Heartland. He then stated that if Kite won't take him out, then he would be happy to take care of the matter.

On the third day of the World Duel Carnival, Gauche resigned from his job as an administrator in the contest in order to compete. Droite later asks Gauche if he's going after Yuma which he confirms as he intends to use his true deck in order to defeat the original Number. And so Gauche and Droite begin collecting Heart Pieces and defeat an unspecified number of Duelists off-screen. This path takes Gauche to also challenge Nelson Andrews to a Duel.

The two exchanged blows with Gauche forcing Nelson to bring out his "D.D. Jet Iron". Gauche revealed his new ace monster, "Heroic Champion Excalibur", ultimately beating Nelson's ace. Nelson then gives one of his Heart Pieces to him and before Gauche leaves with Droite, he tells Yuma to make it to the finals as he wants to fight against him.

At the WDC Finals party Gauche allowed Yuma to enter despite forgetting his invitation, saving him from two bouncers were attempting to eject him. Gauche told them that despite his looks, Yuma is a finalist.

World Duel Carnival Finals
The day of the finals, Gauche greeted Yuma at the Duel Coaster, calling the event the final showdown while urging Yuma to still enjoy himself. When Mr. Heartland explained that Spell and Trap Cards will activate from the coaster itself, even Gauche was surprised, not having known. Later then, Gauche easily defeated one of the finalists with "Heroic Challenger Spartas" and "Riryoku". He told his opponent he was at least ten years too early to challenge him.

After Yuma and Anna Kozuki are cornered by the Fallguys' "Magnet" strategy, Gauche rushes in and managed to defeat Fallguys Coyote with his "Heroic Challenger Extra Sword". He then assists Yuma in Xyz Summoning his "One-Eyed Skill Gainer" and powering it up enough to defeat the Fallguys at the cost of losing Anna from their team. They then enter the final area of the Duel Coaster.

Bouncer
Gauche initially played a "Bounzer" Deck focused on Summoning high-Level monsters in order to punish and relentlessly attack the opponent, reflecting his fiery personality. This Deck is spearheaded by "Photon Strike Bounzer" and was given to him by Mr. Heartland.

Heroic
On the third day of the WDC, Gauche began playing his original "Heroic" Deck, whose names are based on various warriors and weapons, focusing on increasing its own monsters' ATK. This Deck is also said to be Gauche's "real power". He also utilizes various cards to increase his monsters' ATK such as "Riryoku", "Heroic Chance" and "Heroic Challenger Extra Sword".