Death Note (manga)

A Death Note (デスノート, Desu Nōto) is a super natural notebook from the Shinigami Realm. Any human whose name is written in a Death Note will die of a heart attack exactly forty seconds after their name in written (although the cause of death and the time before death can be altered.)

Use
Death Notes are most commonly used by Shinigami, or Gods or Death. If a Shinigami kills a human using a Death Note, that human's remaining lifespan is added to the Shinigami's. As long as a Shinigami kills humans, they can never die. Each Shinigami is only allowed one Death Note, although the series' main Shinigami, Ryuk, obtained two by tricking the Shinigami King into giving him a second Note. Rem, another, female, Shinigami central to the series' plot also has two Notes. Rem's second Death Note was not obtained through trickery, however. Her second Death Note came from Gelus, another Shinigami who died for saving Misa Amane's life.