No it's not a new paper folding technique.
Literally translated the term means "death god".
Basically these guys are Reapers, but with personal issues and sometimes cool Samurai swords.
'Tis the season to read macabre things so here's a sampling of fiction, novels, manga and graphic novels featuring Shinigami and Reapers, From Japan and from U.S. and U.K.
My first encounter with Shinigami was through watching the anime series
Descendants of Darkness by Yoko Matsushita (Manga)
I promptly picked up the Manga series. It details the travails of two humans conscripted into the post of Shinigami after their troubling deaths. They work for a vast and dysfunctional afterlife beaurocracy. Apparently there are things you can't escape even after death, government being one of them. They spend their time leading lost souls to their just reward. As with a lot of Manga it features a high level character angst and "bromance". Google the term and you'll find the wiki and "urban dictionary" definitions.
The trends of manga popularity move fast so the currently hot titles are:
Bleach by Tite Kubo (Manga)
This is the one with the samurai swords, and basically has the same set up as the Descendant's story line; a group of once human protagonists who deal with the problems that arise when the dead hang around too long postponing their final trip out.
We also have an art book from the series, All Color But The Black.
Death Note by Tsugumi Ohba is a darker take on the Shinigami trope.
High school student Light Yagami finds a mysterious notebook. It turns out that it belongs to the Shinigami Ryuk, a very creepy character, sort of a clown with spikes (doubling up on the primal phobias). Ryuk lets Light discover the notebook's special qualities; anyone who's name is written in it dies immediately. Light thinks he can use this power to rid the world of evil men. He doesn't do so well against it's other
temptations. The series eventually becomes a contest between Light and
brilliant detective L who is determined to find the source of the mysterious deaths.
Now on to Euro-American Shinigami/Reaper fiction:
Death and the High Cost of Living by Nail Gaiman. (Graphic Novel)
The Sandman's wicked cool sister Death goes about her daily routine. With some nice character notes and philosophy about life.
The Crow by James O'Barr (Graphic Novel)
James O'barr wrote and drew this stunning piece after a devastating incident occurred in his own life. He has never specifically stated what happened but rumor has it that events that serve as the catalyst to the Crow's creation in the story are somewhat autobiographical. The rest is a surreal exorcism of intense emotions that comes through violence and loss to a sort of trancendance and acceptance. A very dark take on the death giver that isn't for everyone but
certainly should never have gone out of print. It's finally being published again.
For those who like their fiction in a more "realistic" vein:
Darkly Dreaming Dexter by Jeff Lindsay (Mystery Series).
Tells the story of everyone's favorite serial killer/blood spatter analyst. Self appointed reaper of the Miami/Dade district. The story is a great twisty examination of character and the boundaries of being human. I loved the TV series so I sampled the book, the writing is very nice, so I might be taking this trip again in reading the novels.
For more deadly, but oddly charming anti-heroes, I also recommend the Ripley novels by Patricia Highsmith and the Hannibal series by Thomas Harris. (Both in mystery.)
If all of this is just too dang angsty and emo for you, lighten things up with Mort and Reaper Man by Terry Pratchett. (Sci-fi.) A writer who is always good for a laugh and a bit of a think.
I also see that we have a book in the Science Fiction section titled Shinigami, by Django Wexler. It seems to be the beginning of a fantasy epic that deals with...you guessed it...death and the afterlife.
Cheers and happy Hallows to you all,