Yoruichi Shihōin, originating from Soul Society's noble Shihōin Clan, held the title of its 22nd generational head and was regarded as its princess. Raised at the Shihōin Mansion alongside childhood friends Kisuke Urahara and Tessai Tsukabishi, she frequently played beneath the Sōkyoku Hill training grounds constructed by Urahara. Defying noble expectations, she displayed a playful and informal demeanor, instructing her protégé Suì-Fēng to address her without formal honorifics and teasing figures like a young Byakuya Kuchiki, whom she nicknamed "Little Byakuya". She ascended to leadership as Captain of the Gotei 13's 2nd Division and Commander-in-Chief of the Onmitsukidō (Stealth Forces), concurrently commanding its Executive Militia and later Corrections Corps. This tenure marked her as the first woman in these roles. During this period, she mentored Suì-Fēng, imparting advanced combat techniques, and recommended Urahara for promotion to Captain of the 12th Division approximately 110 years before the primary storyline. She dismissed Suì-Fēng's objections about Urahara's perceived laziness while humorously implying romantic interest from her protégé. Her illegal intervention to rescue Urahara and Tessai after Central 46 sentenced them for crimes fabricated by Sōsuke Aizen led to her departure from Soul Society, forfeiting her titles, social standing, and noble status. Relocating to the Human World, she operated from Urahara's shop, often remaining in the form of a black cat for extended periods—an ability unique among Shinigami. This transformation concealed her identity with a male voice. Prolonged use caused her to forget clothing upon reverting to human form, a quirk she deliberately exploited to tease others, notably Ichigo Kurosaki. In the Human World, she guided Ichigo and his allies, training Orihime Inoue and Yasutora Sado to awaken and control their powers by emphasizing their protective instincts. She later led the group into Soul Society to rescue Rukia Kuchiki, navigating the Dangai interdimensional pathway. She intervened to save Ichigo from Byakuya Kuchiki and trained him to achieve bankai using Urahara's accelerated method. Her confrontation with Suì-Fēng revealed lingering resentment over her abandonment, though they reconciled after Yoruichi demonstrated superior mastery of Shunkō—a combat technique combining hand-to-hand martial arts (Hakuda) with kidō energy. Throughout subsequent conflicts, including Arrancar invasions, she employed her expertise in high-speed movement (Shunpo), earning the epithet "Goddess of Flash." Her combat style prioritized martial arts and Shunkō over her unrevealed zanpakutō. She protected allies during incursions in Karakura Town, battling the Espada Yammy Llargo, whose resilient hierro inflicted unexpected injuries. During the Thousand-Year Blood War, Yoruichi reemerged in the Wandenreich's second invasion. She joined Ichigo's group en route to the Soul King Palace, displaying protective behavior toward Orihime regarding the latter's Quincy-designed attire and carrying specialized energy bottles. Her significant contribution occurred in Wahrwelt against the Sternritter Askin Nakk Le Vaar. To counter his lethal "Gift Bad" ability, she activated Raijin Senkei (雷神戦形, Thunder God War Form), an advanced Shunkō state manifesting Raijin's drums and unleashing concentrated lightning. This technique incinerated her upper garments. Though initially overwhelming Askin, the battle remained unresolved. Her personality blends strategic intellect with a mischievous, teasing demeanor. She uses archaic masculine pronouns like "washi" and "onushi," enjoys provoking reactions through nudity or playful banter, and prefers drinking milk, aligning with her feline affinity. She exhibits fierce loyalty, sacrificing her status for Urahara and displaying profound concern for Suì-Fēng's well-being.