Kenpachi Zaraki (更木 剣八 Zaraki Kenpachi) is the captain of the 11th Division within the Gotei 13. His lieutenant is Yachiru Kusajishi. Prior to entering the Soul Reaper ranks, Zaraki resided in District 80, the most lawless district surrounding Soul Society. He became very proficient with swordsmanship while he was there; or at least fighting, and eventually adopting the district's name, "Zaraki", as his surname. After leaving the district he found a small girl who, despite her young age, did not fear his sword. Since she had no name, he named her Yachiru (やちる) in remembrance of the only person he ever admired. At the same time he also took on a name for himself: Kenpachi, the title bestowed upon the strongest swordsman, the one who has killed the most, and a tradition amongst captains of the 11th Division. Yachiru became inseparable from Zaraki from that point further, following him wherever he went, usually clinging to his back.
Kenpachi is the only captain of the Gotei 13 who doesn't know the name of his sword, nor can he use his bankai as a result. In addition, he never uses kidō and rarely uses flash steps. The Bleach Official Bootleg databook ranks his talent in the former as zero. However, he more than makes up for his faults in sheer power. His spiritual pressure is such that, even when wearing the energy-sealing eyepatch, Kenpachi can fight on-par with and defeat other captain-level opponents, even when they release their zanpakutō in either shikai or bankai form. Its concentration is so great that it acts like armor against weaker opponents. During their first duel, he allowed Ichigo one free attack before the duel began. That attack failed to pierce his body, and Ichigo's right hand was wounded in the process. By releasing the bulk of his spiritual pressure, he was also able to cancel out the strongest attack of Maki Ichinose's Nijigasumiduring their battle in the Bount Arc. Despite his seeming disregard for any strategy in his fights and his self-admitted aversion to thinking during battle, Kenpachi is adept at finding and exploiting weaknesses in his opponents' techniques. While he claims to have no sanity or common sense, Kenpachi is actually very perceptive and notices traits in people that others wouldn't notice. For example, he correctly singles out Kaname Tōsen and Gin Ichimaru as the only captains who are afraid to die. During his battles with both Kaname Tōsen and Nnoitra Jiruga, he formulates strategies to work around his disadvantages, such as losing most of his senses or fighting an opponent with six arms. Kenpachi has tremendous quantities of physical strength, proving able to both kick Tōsen through a building in their battle, and grab Ichigo's giant sword barehanded to reel both him and it in for an attack. His physical strength is matched by his endurance; Kenpachi has been shown to easily ignore most of the injuries he sustains in battle, not suffering any debilitation despite suffering multiple lacerations that would disable normal humans. He even allowed himself to be stabbed just to grab Tōsen's blade and break his bankai's effect. The majority of his fight with Nnoitra was a one-sided brawl in Nnoitra's favor, with Kenpachi only taking things seriously when he finds himself in actual danger of dying from the sheer number of lacerations he had received. Kenpachi was proven strong enough to stop Nnoitra's Cero with his bare hands, effortlessly, without showing any sign of injury in the process.