The Shinigami, also known as Death Gods or Gods of Death, are the overarching protagonists of the Death Note franchise. They are an extra-dimensional species who survive by having humans killed to extend their own lifespans, granting them practical immortality.

Ryuk is a Shinigami bored with the activities (or lack thereof) of the Shinigami realm, so he decides to obtain a second Death Note and drop it in the human world for someone to find, hoping to relieve his boredom. He succeeds in tricking the Shinigami King out of a second Death Note.

The name Ryuk appears to be a reference to a character in the popular anime and manga series “Death Note.” In the comics, Ryuk is a demon of death who, bored with his immortality, decides to introduce into the world a notebook that allows its finder to kill anyone by writing their name.

Trivia. Due to many similar characteristics, it has widely been believed that this Shinigami could, in fact, be the reincarnation of Light Yagami. Although this has been debunked, and goes against the series' continuity, Light's reincarnation theory has remained a popular Death Note Myth.