Noriaki Kaetsu, the Ultimate Duelist! 

He tends to pick fights with anyone who shows even the smallest hint of dissatisfaction with him. He is also afraid of failure and will duel with a person as many times as it takes for him to win (which is usually not many, considering his talent.) Easily set off by Daiki Hanabusa, the two argue often, usually about the smallest things. While he loves to duel, it is never his intention to actually harm his partner.