Shinigami

Shinigami (死神, Gods of Death), are a race of extra-dimensional beings who survive by killing humans to extend their own lives. Shinigami in this series are not responsible for every death that occurs; people will eventually die regardless of whether or not the Shinigami pay attention to them, but a Shinigami can end their lives sooner than intended to extend their own lifespan.

Appearance
Shinigami vary widely in appearance, and their bodies are built in ways that would seem impossible by Earthly standards.

Although some Shinigami do not appear to have limbs capable of holding objects (such as hands, feet, etc.), all Shinigami are able to hold and write with a pen in order to use their Death Notes.

Shinigami are capable of flight and use wings as a mode of transportation, especially in the Human World. When their wings are not in use, they retract.

Nature and Abilities
The Shinigami each have a unique personality and level of intelligence. Each Shinigami has his or her own written language, with some opting for letters and some opting for pictures. Takeshi Obata, artist of the series, said that he assumes that all Shinigami can understand the languages of one another. Some Shinigami can also speak, read and write in Earthly languages.

Shinigami have jobs, although they do not have a required amount of work to do. Their main job is to find humans they can take life from, and write their name in their death note. Some Shinigami tend to forget to write names down and some actually die because of this. Shinigami can save other humans they care about if that person is about to die. But the purpose of a Shinigami is to end life, not give it—any Shinigami who violates this nature will perish. Shinigami who die are reduced to dust, and their remaining lifespan is given to the human they saved. Under normal circumstances, a Shinigami will live forever.

Shinigami may be male or female. Shinigami cannot and are not permitted to have sexual relations with humans nor can they have sexual intercourse with each other. They also cannot reproduce. However, Shinigami may have emotions relating to the opposite sex. For instance, Ryuk feels shy and embarrassed when Misa Amane hugs him. In addition, humans cannot easily tell which Shinigami are male and which Shinigami are female, although Shinigami know each other's gender instinctively.

While Shinigami possess senses of taste similar to those of humans, they do not need to eat food. This is because their organs have rotted—or perhaps evolved—to the point where they can no longer gain nutrition from what they consume. In addition, Shinigami do not need to sleep and will not die from a lack of sleep. Ryuk once said that Shinigami view sleeping as "evidence of laziness."

Shinigami can materialize and dematerialize their bodies at will, and are capable of walking through walls and other objects. The only humans that will see this phenomenon are the ones who have touched a Death Note (i.e. only cantact with a Death Note will allow you to see a Shinigami). Physical attacks are useless against a Shinigami, therefor attacking one with something such as a gun will have no affect; the bullets will go right through the Shinigami.

Death Notes and Shinigami Eyes
The main thing all Shinigami have in common is the Death Note. This supernatural notebook allows them to end the lives of humans before their times, adding the human's remaining lifespans to their own. In this manner, a Shinigami can extend their lives indefinitely. To assist in this, their eyes allow them to see the names and remaining lifespans of humans by seeing the faces of their victims. They are able to give Shinigami Eyes to the human they posess, in exchange for half of that humans remaining lifespan (i.e. a human which is supposed to live 40 more years will lose 20 years of their life in order to receive the Shinigami Eyes. The twenty years the human loses are given to the Shinigami that they are making the trade with). Shinigami give this ability to the human by placing their open hand above the humans head.

All Shinigami must possess at least one Death Note, a necessity to extend their lives. Should they manage to come across a second, it should—at least in principle—be returned to the Shinigami King. When a Death Note is dropped in the Human World, humans who pick up the notebook may use that Death Note to kill others. If a notebook ever reaches the human world and is picked up by a human, the Shinigami must accompany the human until they die or the Death Note is willingly given back. Shinigami can explain the purpose of the Death Note to the human, but this is done at their discretion.

Government
The Shinigami King rules and governs all Shinigami, and controls all "distribution" of each and every Death Note given to all Shinigami upon their "creation." Apart from this, it is unknown what, if any, other tasks he performs.

Shinigami have rankings, with the Shinigami King as having the highest ranking. How to Read 13 states that the rankings do not seem to affect the Shinigami's day-to-day activities very much.

Shinigami have an unknown number of laws that they follow. It is unknown who creates these laws, as well as who enforces them. If a Shinigami breaks a law, the Shinigami will face one of nine punishment levels. The severity is least at Level Eight and most at Level One, and a Shinigami will die if anything above Level Three is applied to him or her. Another level more severe than the rest, called the "Extreme Level" also exists. Shinigami may not kill a human in any manner outside of using a Death Note, and doing so merits "Extreme Level" punishment. However, neither the anime nor the manga goes into detail about this part of the Shinigami's lifestyle.

Shinigami Realm
The Shinigami Realm is a barren, dry, and desolate land that is similar to the Purgatory. The realm includes different landscapes and does not have human-like buildings. Shinigami tend to congregate in areas with bone and/or stone structures. There is at least one mountain or cave structure where Ryuk lives alone which is shown in the one-shot special of the anime.

The realm also includes deserts with various holes. The holes, which are shaped like concentric orbs, are littered about the surface. The artifacts have openings which let them see anywhere in the human world from a birds-eye view. These strange objects are what allow Shinigami to take human lives without traveling to Earth. The date that the holes were created is not known.

Conception and Developement
Takeshi Obata, the artist for Death Note, said that he had "a lot of fun" during the creation of the Shinigami. He also felt that the process was "very difficult" since he started "with nothing." He cited the difficulty in his creation of Ryuk as an example. Obata said that at first Shinigami appeared like "beasts" and that with later Shinigami such as Sidoh he designed them to look like crustaceans and insects because "it was easier." Obata said that he felt difficulty in basing characters on animal designs and keeping "the same feeling of the series." Obata said that he considered basing Shinigami on wizards but decided against the idea, and that the rags on some Shinigami serves as a remnant of that concept.

When designing the Shinigami Realm, Obata said that he used "no real design motif" and that he never settled on any concrete appearance. He described the Shinigami Realm as changing appearance in each instance in Death Note, with it sometimes appearing to be a dry field and sometimes appearing to be a room full of bones. Obata says that he likes to think of it as "an abandoned building with chunks of steel sitting around."