Shirogane is a 400-year-old ayakashi who once ruled as the King of Ayakashi near Omiko City. Originating as an ordinary cat in the Edo period, human fear and worship transformed him into a powerful spirit, leading to the construction of a shrine in his honor. Neglect turned his shrine into a popular dating spot, fueling his deep contempt for romance and inspiring the creation of his spiteful gender-swap spell, "Seisei Ruten." His anger reached new heights when the shrine was submerged by a dam project, turning him hostile towards humans and sparking prolonged conflict with exorcist ninjas like Seigen Kazamaki. Typically appearing as a harmless-looking, chubby white cat with closed eyes, Shirogane's true form is a large, fierce feline with fiery or storm-like fur and a rope around its neck. After suffering severe injuries, he temporarily merges with individuals such as Suzu Kanade or Kanade, adopting human features while retaining feline traits like ears and white hair. Once recovered, he reverts to his independent cat form. His personality is marked by pride and formality, often expressed through archaic speech. He harbors a profound dislike for couples, frequently denouncing their behavior as "shameless." Despite his regal bearing, he exhibits pettiness and jealousy, particularly regarding the closeness between Matsuri Kazamaki and Suzu Kanade. He enjoys simple pleasures like Suzu's homemade "Suzu Dango" and is susceptible to catnip intoxication. Over time, his initial predatory instincts soften, developing genuine care for those around him. Shirogane's primary plot involvement begins when he attempts to consume the Ayakashi Medium, Suzu Kanade, to increase his power. Matsuri Kazamaki intervenes, sealing most of Shirogane's spiritual energy into a scroll. In retaliation, Shirogane curses Matsuri with his "Seisei Ruten" spell, transforming him into a girl. Weakened and trapped in his cat form, Shirogane becomes Suzu's pet while plotting to reclaim his sealed power. Repeated attempts to steal the scroll fail, leading him to form uneasy alliances with Matsuri and Suzu against greater threats like Sousuke Hinojiki or the Gogyosen. During battles, he merges with Suzu or Kanade for survival, separating once healed. By the story's end, he abandons his goal of devouring Suzu and collaborates with Matsuri to maintain ayakashi peace. His abilities focus on the "Seisei Ruten" spell, which swaps a target's gender. Only he can reverse it, and the curse becomes permanent if he dies before undoing it. He possesses transformation skills to mimic humans or ordinary cats and can conceal his ayakashi energy. In his weakened state, his combat effectiveness diminishes significantly, leaving him vulnerable to weaker spirits. His sense of smell remains underdeveloped despite his feline nature. Relationships define his development. Initially targeting Suzu for consumption, he grows protective, valuing her kindness and companionship. His dynamic with Matsuri evolves from mutual hostility—rooted in the sealing and gender-curse incidents—to grudging respect and eventual friendship. He avoids Garaku Utagawa, who admires him excessively, and shares a distant yet respectful bond with Reo's grandmother, who fondly remembers their past conversations. His fusion with Kanade during recovery fosters a cooperative partnership. Shirogane occasionally manifests as a censor beam during intimate scenes, reflecting his disdain for romance. His character blends regal authority with comical pettiness, impacting events through magical interventions and complex alliances.