Arima Kishou

Arima has a very calm personality, remaining unperturbed and serene even when surrounded by twenty-five Ghouls or facing the monstrous One-Eyed Owl. He is also an excessively strict mentor, as seen when he reprimands Hirako for being 0.01 seconds late in his attack. As a teenager, Arima displayed the same personality, and also noted that his main hobby was exterminating Ghouls. He has a very cold and calculating approach to exterminating Ghouls, as shown when he was about to finish off Renji, and Yoshimura suddenly appeared; instead of panicking or attacking, he simply greeted the Ghoul.

Arima demonstrated respect for the dead when he reprimanded Itsuki Marude for speaking ill of Kureo Mado after his death. While the author describes him as massive and sadistic, Arima has not shown any signs of sadism at all. He has indicated that despite his stoic personality, he is capable of forming friendships, such as when he borrowed Haise Sasaki's book, and Akira Mado described his feelings toward Sasaki as "paternal love." Arima was also the type of person who would congratulate his opponents; one example was when he did so after Kaneki damaged his Quinque, IXA.

Arima Kishou is a renowned Special Class Ghoul Investigator, known as the CCG's Reaper, or "CCG's Angel of Death," the leader of Squad S3 and the Captain of Squad Arima. He was also the One-Eyed King and, as such, the supreme leader of Aogiri Tree.

He is an undefeated Ghoul Investigator and was previously partnered with Take Hirako.

His investigative skills and combat prowess have earned him the admiration of many investigators, such as Koutarou Amon. However, there are many who are displeased with him because of his numerous achievements within the CCG.

Arima is a tall man with white hair, gray eyes, and pale skin. He is always seen wearing glasses, his face maintaining an apathetic expression, rarely showing any emotion. Arima is also a well-dressed individual, like all Ghoul Investigators, wearing a suit and tie, and when on duty, he wears a white coat.

During his teenage years at Seishin Senior High School, he was mostly seen wearing his standard school uniform. He also always carried what appeared to be a guitar case on his back. However, this was only to conceal his Quinque, Yukimura 1/3, which he used to fight Ghouls. At that time, he had blue hair.