Shinigami

Shinigami varie from one another.

Overview
Shinigami vary widely in appearance, and their bodies are built in ways that would seem impossible by humans standards. Like humans, Shinigami also can die, of sorts by extending the life of a human they care about: the purpose of a Shinigami is to end life, not give it, and hence saving a human is contrary to their nature. Shinigami who die in this manner are reduced to dust, and their remaining lifespan is given to the human they saved.

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 (e.g. a man who would have lived to sixty, but is killed at forty would add twenty years to the Shinigami's lifespan). 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. A human using the Death Note will not receive the same benefits as a Shinigami; while humans can kill people, they cannot increase their lifespans by doing so.

Shinigami usually pass the time by gambling with the only thing they have to trade: years of their lives.

deathnotes
All Shinigami must possess at least one Death Note, a necessity to extend their lives. Should they manage to come across a second, it can be loaned to a human. The Shinigami must accompany the human until they die or the Death Note is willingly given back or reach its expiration date; should the human give the notebook to another human, the same would apply to the new owner. Shinigami can explain the purpose of the Death Note to the human, but this is done at their discretion. They can also offer Shinigami Eyes to the human at the cost of half the human's remaining lifespan; however, while a human with the Eyes can also see the name and lifespan of most humans, they cannot see the lifespan of any Death Note owner, themselves included. Likewise, Shinigami cannot see lifespans of other Shinigami. In addition, Shinigami are forbidden from telling the Death Note owner their remaining lifespan, both because it would cause confusion and because a human aware of their fate might react unpredictably (in a negative way). While in the human world, Shinigami are invisible to everyone except the owner of their Death Note and anyone else who has touched it. Other unrelated Death Note users can only see their specific Shinigami. The ending of both the anime and manga state that all humans, regardless of their actions in life, go to Mu ("Nothingness") when they die, despite the misleadings earlier in the series that only humans who have used the Death Note meet this fate.

Gender
Shinigami may be male or female. Shinigami cannot and are not permitted to have sexual relations with humans; they cannot have sexual intercourse with each other, nor can they reproduce. In addition, humans cannot easily tell which Shinigami are male and which Shinigami are female. Death Note: How to Read 13 adds that Shinigami may have emotions "relating to the opposite sex." For instance Ryuk feels shy and embarrassed when Misa Amane hugs him.

Food
Shinigami do not need to eat food; they possess senses of taste similar to those of humans; as Shinigami do not gain nutrients from food many do not eat. In addition Shinigami do not need to sleep and will not die from a lack of sleep; Shinigami view sleeping as "evidence of laziness.

Language
The Shinigami have a language; 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."Takeshi Obata Production Note: Characters." Death Note: How to Read 13.