darker than black CF

Ten years ago, an inscrutable and abnormal territory known as Hell's Gate appeared in Tokyo, altering the sky and wreaking havoc on the landscape. The heavenly bodies disappeared, replaced by false stars. During this time, people who possess various special abilities emerged. Kept secret from the masses, these individuals, known as Contractors, are able to murder in cold blood. Various nations and organizations around the world use Contractors as spies and assassins, often resulting in violent battles for information. Each fake star has a corresponding Contractor, and they vibrate when their Contractor's power is being used. As such, Contractors are usually identified by their star's Messier catalogue number. However, their abilities are gained at the cost of their humanity. They are implied to lack human emotions which includes no aversions to murder, and they are regarded as extremely rational and logical in their decision making. Contractors are thus named because of their need to always complete a remuneration or payment each time their power is used (ex. eating flowers, breaking fingers, drinking blood). It is not entirely clear what happens to one if he or she fails to complete the remuneration. Contractors are described as being psychologically compelled to complete their remunerative task


Contractor (契約者, Keiyakusha?)
Contractors are individuals who have gained superhuman powers due to the appearance of the Hell's Gate and Heaven's Gate. The existence of Contractors is kept a secret from the general public by most governments around the world, but they are well-known to the higher echelons of society and in the criminal underworld. Contractors possess two other traits that give them a rather sinister reputation: the need to perform remuneration, which is a bizarre, obsessive compulsive "payment" for the use of their powers, and a generally pragmatic, Machiavellian world view. This is described by the Contractors themselves as a lack of emotion in general, but not much evidence exists to verify this claim. Many Contractors exhibit at least some forms of emotion, including love, joy, guilt, and sorrow.

Later in the series it is explicitly revealed that Contractors are fully capable of experiencing emotions, but that those feelings do not play a prominent role in their thought processes. They are described as being totally rational, and totally amoral. The general rules seems to be that they feel no guilt, and they cannot form or retain social bonds. A normal Contractor cares, in essence, only about their own well-being, and everything is reduced to a cost/benefit analysis: Any other issues like laws, emotions, or the question of the sanctity of human life are irrelevant to them.


Contract Payment (契約対価, Keiyaku Taika?, also referred to as "Remuneration" or "Obeisance")
True to their names, all Contractors must pay a price for using their powers, whether they wish to or not. Moreover, it seems that the amount of payment required is dependent on how much the Contractor uses his/her power. Although this payment can be delayed, especially in the midst of combat, it is ultimately unavoidable. Each Contractor has a unique remuneration, reflecting the chaotic nature of the Hell's Gate. Remunerations are typically difficult for the Contractor and range in severity from irritating to painful. However, there have been a few contractors who enjoy their remuneration and at least one who uses it in conjunction with his own ability.
Known remunerations include

* Alteration of age, swiftly growing older or younger
* Arranging pebbles in meticulously straight lines
* Drinking various fluids, such as hot milk, beer, or the blood of children
* Earmarking the pages of a book
* Eating various foods, such as boiled eggs
* Inability to lie
* Intaking and regurgitating objects
* Kissing someone
* Placing the shoes of the victim upside down on the ground
* Regaining human feelings for a brief time
* Self-mutilation or injury, including dislocating fingers and wrist-slitting
* Singing a song
* Sleeping
* Smoking
* Writing poetry