When a human is intended to die, a Grim Reaper would review the individual's life by judging his or her Cinematic Record, which is the recollection of the human's memory. The Grim Reaper then decides whether or not to let the human continue living or to let him or her die. The first option is rarely executed unless the person's life is or would be beneficial to the world. The Grim Reaper collects his or her soul after the human dies.
Humans are able to form Faustian contract with a demon, in order to have their wish fulfilled; the wish is typically something difficult to accomplish, such as revenge. Once the contract forms, the human would bear a mark on his or her person, but the location of the mark may vary from human to human. In a sense, the contract is a "scar" the demon leaves so they would not lose the person they contracted with.
For the duration of the contract, the usual practice is for the demon to serve under the human for as long as it takes. Once the contract is completed, that is the human's wish is fulfilled by his or her demon, the human's soul is eaten by the demon as compensation.
Identified Contracted Humans