the interduction of human:The Commission of Counter Ghoul (????? Guru Taisaku Kyoku, "Ghoul Countermeasures Bureau"), usually abbreviated as CCG, is a federal agency that serves as a criminal investigative body in cases connected to ghouls, as well as to hunt down and imprison or kill any runaway ghouls. In secret, the CCG is run by a family of ghouls disguised as humans. After the Dragon Crisis, the CCG is disbanded and replaced by the Tokyo Security Committee, or TSC, composed of former members of the CCG and ghouls who joined their ranks in their mission to maintain security in the city and develop policies to allow humans and ghouls to coexist.

The strongest character Kishou Arima:Special class ghoul investigator Arima is a legend among both CCG members and ghouls. His prowess in combat has no equal, which has earned him the respect and admiration of his fellow ghoul investigators. As we can see in the OVA Tokyo Ghoul: Jack, Arima has been fighting ghouls since he was very young. The undefeated ghoul investigator is always calmed and composed when fighting ghouls. He looks confident and never shows any sign of hesitation. Arima is not only fast and skilled, he�s also quite resourceful and always finds a way to defeat his opponents (like piercing the floor with his blade quinque to injure Jason and save his friend, Fura Taishi). He can use a variety of complex quinque weapons and he�s so powerful indeed, that he forced the One-Eyed Owl to flee from battle.