Kishio Arima

She is an ally of his, although Eto is a dangerous Ghoul and Arima an Investigator, he keeps Eto's identity a secret for her well-being, he genuinely cares for her and they have a relationship of "friendship and rivalry" despite that he always appears serious and cold with her, which contrasts with the playful personality of the other.

Cold, serene, calm, calculating, with the people he likes or is interested in he is kinder, but without losing that serious touch.

He has gray eyes, white hair, pale skin, is tall and muscular, is very strong, always wears his white uniform, and silver glasses, he is usually serious, rarely showing kindness.

Organization Against Ghouls, better known as CCG. It is in charge of protecting citizens and eradicating Ghouls; normally the organization is merciless and inflexible. It has Ghoul investigators who are in charge of solving cases and dismantling organizations, and in turn, killing as many Ghouls as possible. Some powerful Ghouls do not die and are taken to Cochlea, which is a Ghoul prison where they can be interrogated. They use quinques to defend themselves.

There are several ranges such as these. Subordinates: They follow those of higher rank. Third-class researcher: They are the lowest ranks and are usually colleagues of higher ranks. Second-class researcher: They are higher than third-class ranks, but they are still only peers. First-class investigator: They are assigned small squads of low ranks, they have more weight in the CCG. Associate Researcher: These are researchers who lead an entire squad or their partner in a given case; they are important to the CCG and are quite strong. Special Investigator: They can lead entire missions, command multiple squads, and make important decisions; they are the strongest and most insightful.

Ghouls are creatures with a human appearance that are only differentiated by 4 things.

1. They can only eat human flesh and drink black coffee.
2. When they are hungry or about to use their Kagune, their eyes change to black sclera and red pupil.
3. They have limbs that they can extend from their body to attack; depending on the type and range, they can be lethal.
4. They can regenerate as long as they eat well.

Types of Ghouls Ukaku: These are known for being quite fast and skillful, with acceptable regeneration. Their Kagune is long-range and can fire projectiles, although their resistance is very low. Their Kagune manifests on the upper part of the back, like wings. Koukaku: They are stronger, more skilled, and have greater endurance, as well as incredible regeneration. They specialize in close combat. Their Kagune usually manifests on their shoulders and can reach their wrists as swords or shields. Rinkaku: They are fast, strong and flexible, they have incredible resistance and immediate regeneration. Their Kagune is the strongest with unique properties. They are versatile, fighting in close combat or at a distance. This Kagune usually manifests at the back of the waist as tentacles or derivatives. Bikaku: They are strong, not very skilled but resistant, mostly long range attack, slow regeneration, usually manifest on the lower back in tentacles or variations. Chimera: A Ghoul that has two kagunes inherited from its parents.

Ranges. Rank B: Weakest rank, slow, inexperienced. Rank A: The next weakest rank, can be considered a threat. S-Rank: Latent threat, fast SS Rank: True threat, skillful, fast, strong. SSS Rank: Only special investigators can handle them; they are strong, skilled, and fast. Kakuja Rank: Destructive, almost no one can handle them, dangerous, incredible regeneration, fast and strong, they commit cannibalism among Ghouls, they have no sanity.