Kenpachi Zaraki emerged from the nameless chaos of Rukongai's Zaraki District (District 80), adopting the district as his name. As a child, he discovered a dead Shinigami's Asauchi, imprinting his soul upon it to form his unique Zanpakutō. His defining battle against Retsu Unohana scarred his left eye, awakening his love for combat and subconsciously causing him to limit his power to prolong future fights. He admired Unohana and sought to emulate her style afterward. In District 79 (Kusajishi), he encountered a fearless young girl. He named her Yachiru, honoring Unohana, and adopted the title "Kenpachi," signifying the strongest Shinigami who has slain the most enemies. Yachiru became his constant companion and lieutenant, sharing a father-daughter-like bond. He later recruited Ikkaku Madarame and Yumichika Ayasegawa into his division after sparing Ikkaku's life, imparting his philosophy: "Don’t admit defeat and seek death. Die first, then admit defeat. Survive and think only about killing the one who failed to kill you." Zaraki attained captaincy of the 11th Division by killing the previous captain, Kenpachi Kiganjō, in a single blow under the 3rd Captain Qualification Trial, becoming the eleventh Kenpachi. His appearance is distinctive: tall, muscular, scarred, with long black hair styled into spikes (once adorned with bells) and a tattered, sleeveless captain’s haori. He wears a specialized 12th Division eyepatch designed to absorb his excess reiatsu, ensuring longer battles. His personality centers on a relentless pursuit of challenging fights. He deliberately restrains his strength—fighting one-handed, suppressing reiatsu via his eyepatch, and avoiding lethal blows against weakened opponents—to savor combat. He kills those who refuse to yield, as seen against Kaname Tōsen and Nnoitra Gilga. He values survival over meaningless death, respects formidable opponents like Ichigo Kurosaki (whom he considers a division member after their duel), despises formal tactics, prefers instinctive swordsmanship, and exhibits poor directional sense. During the Thousand-Year Blood War, forced to confront his suppressed power, Zaraki dueled Unohana to the death under Head Captain Kyōraku's orders. After killing her, he awakened his Zanpakutō’s name, Nozarashi, achieving Shikai. This transformed his blade into a massive axe-cleaver capable of cutting through space and obliterating a meteor. Later, against Gerard Valkyrie, he unlocked Bankai, temporarily gaining monstrous strength, red skin, and horned features resembling an oni. This form overwhelmed Gerard but strained his body to near-breaking. In this battle, Yachiru Kusajishi was revealed as a manifestation of his Zanpakutō spirit, disappearing after sacrificing herself to activate his full power. Post-development, Zaraki became more focused and receptive to strategy, organizing division-wide searches for Yachiru. He retained his love for battle but showed increased concern for subordinates. His Zanpakutō abilities include Shikai (Nozarashi), commanded by "Drink," which enhances cutting power to extreme levels, and an unnamed Bankai that boosts physical capabilities exponentially but risks self-injury due to uncontrolled output. Seventeen months post-war, his appearance changed: longer hair without bells and a simplified eyepatch. He participated in restoring Ichigo Kurosaki’s powers and battled Xcution members, maintaining his reputation as the Gotei 13’s fiercest combatant.