Den-noh Coil (Japanese: 電脳コイル, Hepburn: Dennō Koiru; lit. Cyber Coil), also known as Coil – A Circle of Children; is a Japanese science fiction anime television series produced by Madhouse. The series is created, directed and written by Mitsuo Iso, it aired for 26 episodes in Japan on NHK Educational TV between May and December 2007. The story follows a group of children as they use AR glasses to unravel the mysteries of the half real, half Internet city, using a variety of illegal software tools, techniques, and virtual pets to manipulate the digital landscape.
It is a pioneering work that depicts daily life in a world dominated by AR (augmented reality) technology, in which layers created by computer networks are superimposed on the real world. It has received high praise among critics for its fusion of old-fashioned Japanese scenery and urban legends, a modern version of the Japanese folklore Kaidan, with a futuristic worldview, and for its story of children playing in an augmented reality world using a device called "Den-noh Megane" (cyber glasses), as if anticipating the subsequent emergence of smart glasses.
Den-noh Coil has won several awards, including the Grand Prize of the 29th Nihon SF Taisho Award, the Best Media of the 39th Seiun Award, both in 2008, and the Excellence Award at the 11th Japan Media Arts Festival in 2007.
Contents
Plot
The year is 2026, and it has been 11 years since the "Den-noh Megane" (cyber glasses), a wearable computer in the form of glasses that uses AR technology, became widespread throughout the world. The glasses allow information from the Den-noh world to be superimposed on and manipulated in the real world.
There are pets and tools that use Den-noh technology, and the telephone and Internet are used through Den-noh Megane. Children could no longer remember the time when they could see the world without looking through glasses.
Just before her last summer vacation in elementary school, Yuko Okonogi, a.k.a. Yasako, moves from Kanazawa City, the capital of the prefecture, to Daikoku City, a provincial city with an ancient capital lined with historic shrines and temples, but also equipped with the latest electronic infrastructure.
There she meets another Yuko, Yuko Amasawa, also known as Isako, who has the same name and is the same age but is in contrast to her.
At her new school, Yasako meets a group of children with rich personalities and experiences a series of strange events that occur in the Den-noh space. Yasako's new classmates, Fumie, Daichi, and Haraken, belong to the Children's Detective Bureau run by her grandmother, and as she investigates urban legends about dangerous beings in Den-noh space with them, she learns that one of their friends may have died because of her pursuit of that being. Most frightening of all, Yasako has lost all memory of her previous time in Daikoku City.
Characters
Yuko Okonogi (小此木 優子, Okonogi Yūko)
Voiced by: Fumiko Orikasa (Japanese); Hilary Haag (English)
Nicknamed Yasako, which is another reading of 優子 meaning "gentle girl". With her sister Kyoko and her two parents, Yasako moves to the city of Daikoku to live with her grandmother, Megabā. Yasako is a sweet and passive girl who follows the lead of Fumie, who eventually initiates her into Megabā's Coil Cyber Detective Agency as its eighth member. Yasako has been to the city of Daikoku seven years ago for her grandfather's funeral. A pair of Den-noheyeglasses and the virtual pet Densuke were left to her as a memento. During her time in Daikoku, she coincidentally wandered into the Coil Domain where she befriended a young boy with the codename 4423. After Yasako returns to live in Daikoku, her hazy memories of that enigmatic friendship gradually return to haunt her. Her father Ichirō works at a Dennou technology company, Megamass, which deploys Searchmaton in Daikoku. Her birthdate is October 12, 2015.
Yuko Amasawa (天沢 勇子, Amasawa Yūko)
Voiced by: Houko Kuwashima (Japanese); Monica Rial (English)
Nicknamed Isako, which is another reading of 勇子 meaning "brave girl", Yuko Amasawa is a powerful type of hacker known as an "encoder" (暗号屋, angōya) who is able to manipulate the electronic infrastructure through sophisticated chalk patterns. Rumored to have familial ties to an AR technology company, Isako uses a Brain-Computer Interface to interact with the virtual world—a function hidden inside the hardware of AR visors and eyeglasses. Isako is, on the surface, extremely arrogant and antisocial, perceiving human relationships strictly as hierarchies of power and manipulation. Isako relentlessly chases special illegals in order to collect kirabugs. She is secretly driven to this task in the hopes of finding her brother in "the other side". Her birthdate is April 4, 2015.
Kyoko Okonogi (小此木 京子, Okonogi Kyōko)
Voiced by: Akiko Yajima (Japanese); Kira Vincent-Davis (English)
Den-noh pets
Densuke (デンスケ)
Voiced by: Tomohisa Aso (Japanese); ? (English)
A dog-shaped petmaton owned by Yasako. He was a gift from Yasako's grandfather, who was involved in Den-noh medicine.
Anti-illegal Den-noh object software
Searchmaton (サーチマトン, Sāchimaton)
Searchmaton, Searchy (サッチー, Satchī) for short, is a bot and antivirus software deployed by the Den-noh space Administration of Daikoku, whose task is to debug and maintain the virtual side of the city. Its secondary function is to seek out and disable illegal AR devices, software, and viruses, making it a menace to the characters of the series. Searchmaton, which strikes fear into the hearts of children, ironically, calls out them the cute catch phrase "Me Searchy!" (僕サッチー, boku Satchī) given by Yasako's father, who was involved in its development, with a smiley face also drawn by him. While Searchmaton can patrol the city streets freely, it is prohibited to enter private property such as houses, and other spaces such as temple grounds and schools, because they lie outside of the responsibility of the postal bureau, which has jurisdiction over Search. Searchmaton can deploy up to four spherical drones, Q-chan (キュウちゃん, Kyū-chan; lit. Ball-chan), to aid in its task.
Searchmaton 2.0
A cube-shaped Searchmaton with upgraded armament and shields, capable of running higher-level formats than Searchy. It has a base unit and six extensions like Searchy, but usually only the extensions act like Q-chan. In emergencies, the six units can combine with each other or with the base unit. It is under the jurisdiction of Megamass and the Den-noh Bureau, and is sent out only at the discretion of Megamass or at the request of the government. It can enter shrines and schools beyond the boundaries of the vertical administration, and it can even invade private property with special permission.
Themes
Den-noh Coil is an anime about children growing up in the near future, when semi-immersive augmented reality (AR) technology has just begun to enter the mainstream. It deals with various advanced and new technologies of the future that were not well known at the time of its broadcast, such as wearable computers, self-driving car technology, and virtual currency. The series takes place in the fictional city of Daikoku, a hotbed of AR development with an emerging citywide virtual infrastructure. It follows a group of children as they use AR glasses to unravel the mysteries of the half real, half Internet city, using a variety of illegal software tools, techniques, and virtual pets to manipulate the digital landscape. The title of the show itself, Den-noh Coil, refers to a dangerous separation of one's digital self from the physical body. Dennō means "computer" and is analogous to the archaic English term "cyberbrain". In the series, the word is used to differentiate between virtual and real, e.g. "cyber cat". Due to the animators involved in its production and its unusually high-profile television broadcast time slot, Den-noh Coil was highly anticipated.
The theme of Den-noh Coil using AR technology in mysterious stories and urban legends such as Illegal, Michiko, and "the other side", and above all, "people's feelings and memories" associated with "places".
"The other world" visualized by Den-noh glasses is a form of "the past" that has not been updated to the present, a metaphor for the "memories" and "remembrances" that people leave behind in places and sometimes, people are unable to break free from the past and are attracted to "the other world" (Isako, who cannot accept her brother's death, and Haraken, who runs after the shadow of Kanna died in an accident).
In other words, the world shown by Den-noh glasses is the thoughts of such people, and through the technology of AR, Den-noh Coil reinterprets folklore and asks how people should confront their past. According to the series director, Mitsuo Iso, a major theme in Den-noh Coil is the distance between the characters, such as Yūko's inability to feel the fur of her own virtual pet, in addition to all the relational tensions and divides of understanding between the characters in the series. In Iso's translated words, it conveys how "there will always be a distance between people, and even between things that seem within ones' reach and that one must walk down a long, thin and winding road before they reach one's heart. There are tons of obstacles. It's in fact like the roads in towns of old."
Setting
Den-noh Coil (電脳コイル, Dennō Koiru; lit. Cyber Coil)
This is a phenomenon of unknown cause in which the Den-noh body separates from the real body when certain conditions are met. When the Den-noh body separates, the real body loses consciousness and appears as a pitch-black shadow through the glasses, with the words "NO DATA" displayed on the surface.
Den-noh Glasses (電脳メガネ, Dennō Megane; lit. Cyber Eyeglasses)
A glasses-type wearable computer that is all the rage among children. They called simply Megane (eyeglasses). The visor is always connected to the Internet, which allows them to see the Den-noh materials. So they can see virtual views overlaid on real cityscapes, use Den-noh items, and play with Den-noh pets. They can also make phone calls by using gestures, or use their glasses as a PC by projecting holographic images of monitors and keyboards into the air to control them. They can also listen to sound through futuristic ear monitors embedded in the vines of their glasses.
Den-noh space
It is often referred to simply as "space," in which the Den-noh materials exist. The world in the work is a ubiquitous society that uses it. It is also used for fully automatic control of transportation, and is greatly involved in the daily lives of people who do not use glasses. It is provided by Megamass, and in Daikoku City, it is managed by Daikoku City Hall as an administrative service under the jurisdiction of the Postal Bureau. For this reason, Megamass employees are seconded to the city hall.
Den-noh Navi
A navigation system for self-driving cars using Den-noh glasses.
Den-noh materials
A general term for anything that can be seen by wearing Den-noh glasses, including holograms for PC operation, Den-noh pets, and Den-noh items. People can see the images and hear the sounds they make, but do not feel any physical touch.
Media
Anime
Originally, the Den-noh Coil project was to be an animated film directed by Mitsuo Iso. In January 2007, Madhouse announced that the project was an animated series based on the light novel of the same name. The series was a project Iso had been working on for over a decade and his directorial debut. It aired 26 episodes from May 12 to December 1, 2007, on NHK Educational TV.
Australian distributor Siren Visual released the series on streaming in July with English subtitles, and on DVD in September in 2011. Maiden Japan released the series on Blu-ray and DVD with English dubbing in North America in June 2016. It was released on Netflix in late January 2022 to promote The Orbital Children, a 2-part film directed by Mitsuo Iso.
Opening theme
"Prism" (プリズム, Purizumu)
Composed and performed by Ayako Ikeda; arranged by Tatoo.
Ending theme
"Pieces of The Sky" (空の欠片, Sora no Kakera)
Composed and performed by Ayako Ikeda; arranged by Tatoo.
Light novels
A thirteen light novel adaptation of Den-noh Coil, written by Yūko Miyamura, was published by Tokuma Shoten. The first volume was released on April 4, 2007, and the last volume was released on November 20, 2010.
Manga
A spin-off manga illustrated by Kuze Mizuki, titled Den-noh Coil The Comics, was first published with a single chapter in Shogakukan's shōjo manga magazine Ciao on July 3, 2007, and later continued and completed in a tankōbon volume released on October 31 of the same year.
Other media
The PC browser game Den-noh Coil: Hōkago Tantei Kyoku (電脳コイル 放課後探偵局, lit. Den-noh Coil: After School Detective Agency), developed by GameOn was available from January 25, 2012, to July 12, 2013.
A production art book titled Den-noh Coil Archives book was released in Japan in 2018, It included anime production materials such as early character designs, background art for each episode, image boards, and other materials from the series.
Reception
THEM Anime Reviews gave it a 5 out of 5 stars calling it "The animation is consistently excellent throughout, and the music is great. The characters are also well constructed and worth caring for. The world of Den-noh Coil is convincing and realistic. The story has a very complex puzzle at its heart, and waiting for all the pieces to come together is rewarding. Intelligent and superbly animated, Den-noh Coil will satisfy the appetites of fans who want something more from their anime". Anime News Network praised the series for its unique concepts, story, animation and technology, describing it as "Concepts that are years ahead of their time, engaging characters and story, good use of CG with strong character development, engaging mysteries, tense and thrilling action sequences".
Newspaper Mainichi Shimbun suggested the technology shown in the series would have a great influence on the future, comparing it to the way Snow Crash influenced the development of Second Life. It also praised the series for showing technology that was very Japanese, and concentrating on how the youth grow. Mike Toole of Anime News Network named Den-noh Coil among his top 10 overlooked anime of the 2000s, calling it "sort of a spiritual successor to last decade's Serial Experiments Lain" and "one of those shows where the end of each episode triggers immediate desire for the next episode." John Hanke, former head of Google's Geo Product division, founder of software company Niantic, Inc. and creator of Ingress & Pokémon Go, is a fan of Den-noh Coil and Ghost in the Shell.
In 2008, the Virtual World Institute of GLOCOM; found new possibilities in the augmented reality depicted in Den-noh Coil, which overlays a network on the real world rather than in virtual reality.
They then discussed the feasibility of infrastructure to support society and the form of organization to run society as an exploration of the future society.
At the time, with the Second Life boom that occurred around 2006, there was a lot of talk about a virtual society, but in Europe and the U.S., the idea of creating a completely different world where people could do whatever they wanted, like the metaverse in the science fiction novel Snow Crash.
In contrast, they saw in this work the possibility of not only that, but also the possibility of a virtual world embedded in the real world.





