Amon, Koutarou

A first class police investigator who investigates Ghouls, also known as a Dove. He comes to the 20th ward with his mentor, Mado Kureo, to investigate Ghoul incidents in the area. He has a strong sense of justice, fervently believing it is the right and moral thing to do to exterminate the Ghouls. He hunts the Ghouls in order to prevent more human children from becoming orphaned like himself, and he often works after hours to achieve his goals.

Due to a personal experience as an orphan during his childhood, Amon has come to the conclusion that this world is wrong, so he has made it his task to change the world. Because he thinks it's the ghouls that are twisting the world, he views the eradication of all ghouls as a way to mend this world. After being spared by Ken Kaneki, Amon has started to question the righteousness of his crusade.

He has a certain interest in the two ghouls Rabbit and Eyepatch.

He wields a "Quinque" (a weapon made from the "Kagune" of a Ghoul) that has the appearance of a pole-arm with a large cylindrical bludgeon at the end.

[Spoiler] He is disarmed by Kaneki near the end of the Tokyo Ghoul manga and taken away by Aogiri, leaving his fate unknown.

In chapter 66 of Tokyo Ghoul:re, it is revealed that he is alive and is seen with a kakugan active in his right eye. Proving that he is now a half-ghoul. [/Spoiler]

(Source: Tokyo Ghoul Wikia)