Shikigami (式神?, also read as Shiki-no-kami, 式の神) is the term for a being from Japanese folklore. It is thought to be some sort of kami, represented by a small ghost. The belief of shikigami originates from Onmyōdō.
Shikigami are conjured beings, made alive through a complex conjuring ceremony. Their power is connected to the spiritual force of their master, where if the invoker is well introduced and has lots of experience, their shiki can possess animals and even people and manipulate them, but if the invoker is careless, their shikigami may get out of control in time, gaining its own will and consciousness, and can even raid its own master and kill them in revenge. Usually shikigami are conjured to exercise risky orders for their masters, such as spying, stealing and enemy tracking. Shikigami are said to be invisible most of the time, but they can be made visible by banning them into small, folded and artfully cut paper manikins. There are also shikigami that can show themselves as animals or birds. 
Shikigami in modern subculture
Shikigami are a popular motif in modern anime and fantasy-novels, such as Kekkaishi, Touhou Project, Shōnen Onmyōji, Teito Monogatari, Inuyasha, Natsume's Book of Friends, Nurarihyon no Mago, Spirited Away, Bleach, Mahou Sensei Negima!, Tokyo Ravens, Kamisama Kiss, Kantai Collection, Descendants of Darkness, and Inazuma Eleven GO. In Teito Monogatari, the first work widely credited with sparking the contemporary popular interest in onmyodo mysticism, they are represented as shape shifters formed from parchments with the pentagram (Seiman) inscribed upon them. In Inuyasha, they appear as little paper manikins, causing a ruckus; or as trickster imitating demons in attempt to lure the heroes away. In Natsume's Book of Friends, they appear as little paper tools who spy, track and sometimes trap yōkai and occasionally the title character for one of the series' exorcist. In Nurarihyon no Mago the shikigami appear as battle spirits used as weapons by the onmyōji against the yōkai. In Spirited Away the shikigami appear as a swarm of little paper dolls, attacking Chihiro's friend, Haku. They play a minor role in the sequel of Inazuma Eleven GO as part of a hissatsu technique by the goalkeeper in one of the Feida's teams named Garu. In Kantai Collection, light aircraft characters such as Ryūjō, Hiyō-class aircraft carriers Jun'yō and Hiyō, Akitsu Maru (after remodelling), Unryū-class aircraft carriers Unryū, Katsuragi, and Amagi are also able to use shikigami to transform into aircraft.
- Norman Havens, Nobutaka Inoue: An Encyclopedia of Shintō (Shintō Jiten): Kami (= Volume 1 of: An Encyclopedia of Shintō.). Institute for Japanese Culture and Classics Kokugakuin University, Tokio 2006, ISBN 4-905853-08-7, page 84–90.
- G. Rodney Avant: A Mythological Reference. AuthorHouse, Bloomington 2005, ISBN 1-4184-9278-7, page 356.
- Patrick Drazen: A Gathering of Spirits: Japan's Ghost Story Tradition: from Folklore and Kabuki to Anime and Manga. iUniverse, New York 2011, ISBN 1-4620-2942-6, page 224.
- Kazuhiko, Komatsu. "Seimei jinja" 28-61
- Kazuhisa Fujie, Martin Foster: The Inu-yasha Experience: Fiction, Fantasy And Facts (= Volume 5 of: Mysteries and Secrets Revealed!.) DH Publishing, Tokio 2004, ISBN 1-932897-08-9, page 119.