Haise Sasaki, originally university student Ken Kaneki, became an artificial one-eyed ghoul after organ transplants from ghoul Rize Kamishiro forced him to exist between human and ghoul societies. Initially shy and bookish with a deep fear of isolation rooted in his mother’s death, he worked at Anteiku coffee shop while struggling to reconcile his human identity with his ghoul nature, including the need to consume human flesh. Captured and tortured by Aogiri Tree’s Yamori, Kaneki underwent drastic changes: his hair turned white from stress, and he adopted a colder, ruthless demeanor. Embracing his ghoul abilities to protect others, he cannibalized ghouls to gain strength, developing an incomplete kakuja armor and earning the moniker "Centipede." Severely injured by CCG investigator Kishou Arima during the Anteiku raid, Kaneki suffered amnesia and partial blindness. Rehabilitated by the CCG as Haise Sasaki, he became a First Class Ghoul Investigator mentoring the Quinx Squad. Haise exhibited a gentle, cooperative personality distinct from Kaneki, with anxious mannerisms like head-scratching and a habit of using puns. He showed mercy to ghouls while rejecting his own ghoul half, battling internal conflicts as fragments of Kaneki’s memories surfaced. His white hair with black streaks symbolized this fractured identity. Confronting ghoul Eto during the Tsukiyama Family Extermination Operation restored Kaneki’s memories. Shedding the Haise persona, he reemerged as the emotionally detached, self-destructive "Black Reaper," marked by a black uniform and nihilistic outlook. He defected from the CCG to rescue imprisoned ghoul Hinami Fueguchi. After defeating Arima, Kaneki claimed the title "One-Eyed King," forming the organization Goat to bridge human-ghoul conflicts. His physical state deteriorated upon transforming into the "Dragon"—a colossal, uncontrollable kakuja entity—after consuming artificial half-ghouls. This form emitted toxic ROS gas that mutated humans and ghouls. Rescued by allies including Touka Kirishima, he reconciled his dual nature, married Touka, had children, and achieved peace between species. Kaneki’s abilities centered on his rinkaku kagune (tentacle-like limbs) and regenerative healing. His kakuja escalated from partial armor to the city-scale Dragon, which spawned poisonous offspring and required extraction from its core to halt its rampage. His psychological journey involved oscillating between human empathy and ghoul brutality, accepting trauma, and ultimately balancing both identities for strength.