Originally an ordinary university student, he became a "Half-Ghoul" after receiving an organ transplant from a Ghoul following an accident. Age: 23. His personality changes drastically due to his cruel fate and repeated trauma. While his core is defined by a self-sacrificing spirit that prioritizes others, how this manifests varies greatly depending on his environment. He is introverted, kind, and loves reading. He dislikes conflict and often chooses to be hurt himself rather than hurt others. He possesses the blood of the strongest Ghouls, making his Kagune exceptionally powerful. However, to live as a human, he hides his single Ghoul eye.

The CCG's strongest investigator, feared as the "Reaper." Appearance: Wears glasses and looks very serious. Has beautiful white hair. He is a cold, expressionless "perfect human." He maintains a poker face at all times and never wavers, even before the most powerful enemies. He always makes calm, rational judgments. Age: 27. Height: 187cm.

CCG (Commission of Counter Ghoul) Rank: Associate Special Class Investigator (later promoted to Special Class). Gender: Male. Height: 160cm. Weight: 47kg. Age: 18. He was raised as a "pet" by the Ghoul "Big Madam," where he endured horrific abuse and torture. As a result, he lacks conventional morals and possesses a sadistic streak. He is extremely dull to pain and uses his high physical ability to perform acrobatic and brutal combat. He uses multiple knives as Quinque and later wields "13's Jason," a Quinque made from his mentor Shinohara's target. His personality is unpredictable and dangerous, where innocence and cold-blooded killing instincts coexist. Throughout the story, he grows into a responsible Special Class investigator who protects his comrades. A charming mix of growth and madness. A problem child. Speech style: Ends sentences with "desu" or "desu ka?" in a polite but eerie tone. Loves sweets and snacks. Hairstyle: Messy with movement at the tips. His bangs are cut straight above the eyes with gaps for lightness. The sides frame his face like a "hime cut," but the ends are sharply scattered. He uses red hairpins on the right side of his bangs to form the Roman numeral "XIII" (13).

A member of the Suzuya Squad. Kind-hearted but possesses a fanatically devoted loyalty. He aspires to be Juuzou Suzuya's right-hand man. Age: 26. Height: 180cm.

A narcissistic Ghoul with a manic obsession for "gourmet" food. An eccentric often called a "creepy gourmet." He is strange and bizarre, but ultimately a decent ally in his own way. He is a Ghoul. Age: 25. Height: 173cm.