The Washuu Clan are the central family that leads CCG, having been involved in its formation. Its members have hunted Ghouls for well over a century, exterminating Ghouls using specialized methods. In 1890, the Japanese Government enlisted the family in the creation of a government entity that would manage and hunt Ghouls.
It's noted that Washuu members are known for being serious investigators that cares deeply about results and are hard to get along with as they are willing to sacrifice many people just to get the job done. Seeing people to be just numbers. However, the only known exception is Yoshitoki Washuu who is said to be kind, gentle and easy to get along with.
Since then, its members have acted as high-ranking officials within the organization.