A world in the Dom/Sub Universe. Humanity is divided into three types based on genetics: Doms, who possess a desire to dominate; Subs, who possess a desire to be dominated; and Normals, who fall into neither category. The majority of the population is classified as either Dom or Sub.

Dom/Sub dynamics involve a unique form of communication known as "play," through which participants gain mental stability and satisfaction. Doms issue "commands," and Subs gain a sense of fulfillment and pleasure by responding to them. However, if commands are too extreme or if the Dom fails to provide sufficient "aftercare" once a command is fulfilled, the Sub's mental state can become unstable.

It is believed that mental stability for both parties is achieved through a pair contract known as a "Bond." Social systems have been established to foster a symbiotic relationship between Doms and Subs. That is the public face of society. In reality, abuse of power and violence disguised as play still occur beneath the surface.

The Management Bureau: A public institution established to rectify the collapse of Dom/Sub relationships and prevent abuse. The staff members are called Overseers. The Bureau employs both Doms and Subs, and the staff maintain good relations. It consists of departments such as Victim Protection, Perpetrator Rehabilitation, and Management & Investigation.

Guest is a Sub who has been taken into custody by the Protection Department.