Chaos;Head

Chaos;Head (カオスヘッド), stylized as ChäoS;HEAd, is a Japanese visual novel developed by 5pb. and Nitroplus that was released on April 25, 2008 for the PC. A port of the game, named Chaos;Head Noah (カオスヘッドノア), for the Xbox 360 console was released on February 26, 2009. The game is described by the development team as a "Delusional Science NVL" (妄想科学NVL). The game's premise revolves around a high school student named Takumi Nishijō who unknowingly walks into the scene of a gruesome murder on his way home. More mysterious events starts happening afterwards as more gruesome murders occur in the area. Takumi struggles to cope with reality and the delusions he experiences as he tries to avoid getting caught by the perpetrator behind the chain of murders.

The game's story has been adapted into a manga that started serialization on May 21, 2008 in ASCII Media Works' shōnen manga magazine Dengeki Daioh. A second manga adaptation that focuses on Sena Aoi and Kozue Orihara began serialization in Media Factory's seinen manga magazine Monthly Comic Alive on August 28, 2008. It has been decided for this adaptation to be a side story to the original visual novel. A third adaptation will begin serializing in Jive's shōnen manga magazine Comic Rush magazine on September 26, 2008. The anime adaptation of Chaos;Head was announced in the September 2008 issue of Comic Alive. The anime began airing in October 2008 and is produced by Madhouse.

Gameplay
The gameplay of Chaos;Head, like other visual novels, requires little player interaction as the game is primarily made up of text dialogues. The player only needs to read and click through the text to advance through the game. The text that is displayed on the screen depicts conversations between different characters or their thoughts.

Chaos;Head presents choices to the player through a unique "delusional trigger" (妄想トリガー) system. This system presents the player with three choices relating to Takumi's psychological state. Two cardiac cycles will be displayed on the screen. A green, stable one will be on the top left hand corner and a red, unstable one will be on the top right hand corner. The third choice is not visible to the player as it requires no player interaction. The player may choose to click on the green or red cardiac cycle, or to simply proceed through the game without selecting either of them. The player is not required to make a choice immediately as the two cardiac cycles will remain on the screen until a predetermined number of lines has been passed since they appeared.

Selecting the cardiac cycles will often decide what kind of delusions Takumi will experience. The stable choice often shows a happy or humorous scene whereas the unstable choice will show very negative scenes possibly with gore and violence added. Yes and no questions also show up at times although they are much less frequent than the delusional triggers.

Setting and themes
Chaos;Head primarily takes place in Shibuya, Tokyo. Many of Shibuya's physical locales like its busy pedestrian scramble and the Loft building appear in the game although their names have been altered slightly. Some notable Internet websites like Wikipedia, 2channel, YouTube, Google, and Yahoo! also show up in the game with modified names as We-Key Pedophiria, @-channel, MewTube, Deluoode , and Taboo!.

As the title implies, psychological themes relating to one's psyche and mind plays a large role in Chaos;Head. Delusions and the method of projecting one's own delusions onto the physical world, or onto someone else's visual system, is a key driver behind the story. Other scientific themes such as the concepts of matter, antimatter, and the Dirac sea are also brought up.

Story
Chaos;Head's story is set in 2008 in Shibuya and is centered around Takumi Nishijō, a high school student at the private Suimei Academy, and the strange and brutal murders that have recently occurred in the Shibuya area, known as the "New Generation" (ニュージェネレーション) Madness. The story begins on September 28 with Takumi talking to an online friend called Grim (グリム). Grim is trying to bring Takumi up to speed about the recent New Generation events since Takumi is not interested in local or international news. A person named Shogun (将軍) joins the chat room midway through Grim and Takumi's conversation. After Grim leaves the chat room, Shōgun begins to talk. He speaks in a very cryptic and confusing manner, leaving Takumi nervous. He then sends Takumi a barrage of image links, one of which appears to be of a brutal murder of a man being pinned by stakes to a wall.

The next day, Takumi comes across a real life murder scene. Witnessing a mysterious pink-haired girl pinning a man up by stakes in an alleyway, he immediately realizes he is witnessing the very murder detailed in the pictures he received the day before. Convinced Shogun is targeting him and the girl he saw committing the murder is somehow connected to him, Takumi tries to avoid getting involved with other New Generation events. However, as Takumi begins attempting to distance himself from the crime he witnessed, he soon catches interest of the police.

With the police suspecting him, and himself convinced that he is being targeted by Shogun, Takumi finds himself caught in a spiral of delusions and paranoia, as he desperately tries to keep himself safe and figure out why he is apparently being targeted. He eventually comes into contact with several other people related to the events, including the girl he saw committing the murder himself. Unsure of what is real or who he can trust, Takumi finds himself thrust into a much larger scheme than he ever thought possible, as the mysterious company NOZOMI carefully plots something from behind the scenes.

Main characters

 * Takumi Nishijō (西條 拓巳)
 * Takumi is the main character of the series. He is a hikikomori and only attends school in order to fulfill the minimum for graduation requirements. He often and repeatedly notes that he is not interested in girls in the three-dimensional world and avoids conversations with others whenever possible. He prefers to engage in watching anime, playing eroge, and massively multiplayer online role-playing games. He is a second-year student at Suimei Academy (翠明学園). [[Image:CHmainchar.jpg|right|thumb|200px|The main characters from Chaos;Head. From left to right: Sena, Kozue, Nanami, Takumi, Rimi, Ayase, Yua]]


 * Rimi Sakihata (咲畑 梨深)
 * Rimi is a mysterious pink-haired girl that Takumi encounters at the crime scene on his way home. Rimi was wearing Suimei Academy's uniform at the time and appeared to recognize Takumi. She later claims to have known Takumi for a long time, something that only Takumi seems to be unable to remember, yet she claims to have no idea what he is talking about in regards to the murder.


 * Nanami Nishijō (西條 七海)
 * Nanami is Takumi's younger sister and is a first-year Suimei Academy student. She often puts up a strong front and seems to argue with her brother whenever they meet but she is actually really concerned about him.


 * Ayase Kishimoto (岸本 あやせ)
 * Ayase is a second-year Suimei Academy student by day and vocalist by night. She sings for a popular indie rock band named "Phantasm" (ファンタズム). Her stage name is "FES". The lyrics in her songs appears to describe the events of the recent murders, leading the police to see her as a potential suspect. She is also the most spiritual and eccentric of the main characters.


 * Yua Kusunoki (楠 優愛)
 * Yua is a third-year student at Suimei Academy who seems to be stalking Takumi but later seemingly befriends him. She seems to be quite into anime and manga. However, this is all later shown to be an act where she is investigating him as she suspects Takumi of being the criminal behind the recent murders.


 * Sena Aoi (蒼井 セナ)
 * Sena is a third-year student at Suimei Academy. Takumi first encounters her in a hallway at school but quickly excuses himself after facing her ominous glare. She is often seen standing around Shibuya holding a very long sword and eating a light blue ice pop.


 * Kozue Orihara (折原 梢)
 * Kozue is a second-year student that transfers into Suimei Academy early on in the story. She is not shown to be speaking but appears to have telepathic abilities. She calls herself Kozupii.

Other characters

 * Grim (グリム)
 * Grim is Takumi's online friend, who talks to him almost everyday through their mutual favorite online game, Ensue. He often encourages Takumi to have more courage while dealing with the "third dimension", and supports Takumi throughout his many ordeals. He is very interested in the New Generation incidents and frequently updates Takumi with gory details regarding the murders. As his interests in anime, manga, and games are very similar to Takumi's, the two get along very well, although later his frequent use of the "Whose eyes are those eyes?" phrase seriously bothers Takumi.


 * Shogun (将軍)
 * Shogun is a mysterious person that Takumi meets during a chatting session. He sends gore pictures relating to the New Generation incident to Takumi, the equation "fun^10xint^40=Ir2", and the phrase "Whose eyes are those eyes", which Takumi often used. This event gives Takumi paranoia throughout the story, thinking that Shogun is spying on him and trying to kill him. His true identity is one of the driving mysteries of the story.


 * Orgel Seira (星来 オルジェル)
 * Seira is the main heroine from Takumi's favorite anime "Blood Tunes the Animation", and also Takumi's favorite character. Occasionally, she shows up in Takumi's delusions, trying to deviate him from reality and push him to be a shut-in. Her delusional appearance is in fact Takumi's own weaknesses given voice.


 * Daisuke Misumi (三住 大輔)
 * Daisuke is the only friend Takumi has in his class. A handsome man, he is well liked by almost all girls in his school.


 * Yasuji Ban (判 安二)
 * Ban is a detective of the Tokyo Metropolitan Police Department Criminal Investigation Division. He initially suspects Takumi of being the criminal behind the New Generation murders, but he soon finds himself investigating other leads, including the company NOIZOMI and a well-known religious cult.


 * Mamoru Suwa (諏訪 護)
 * Mamoru is a detective of the Tokyo Metropolitan Police Department Criminal Investigation Division. He is Ban's junior, and Ban considers him to be both an underling and a friend. His hobby is watching movies, especially Spark Wars, a parody to Star Wars.


 * Genichi Norose (野呂瀬 玄一)
 * Norose is the president of the NOZOMI Technology Group. His role is kept a mystery throughout most of the story, until he is revealed to be the main antagonist, and the creator of the Noah II device, capable of manipulating brain waves and causing delusions to become reality. He has been gathering people with special psychic powers as young children, and torturing them for the sake of completing his twisted desires.

Development
Chaos;Head is a collaborative production between 5pb. and Nitroplus with additional assistance from Red Flagship. The original concept art and scenario came from two 5pb. staff members, Yukihiro Matsuo and Naotaka Hayashi respectively. The character designer was Mutsumi Sasaki and Choco handled the product's design. 5zizz studio contributed the music to the game and Nitroplus handled the development and production of the game. Chaos;Head was temporarily named as Gigalomaniacs (ギガロマニアックス) when it was first announced. The decision to port the game to the Xbox 360 was decided around June 2008. Ayumi Tsuji, the voice for Kozue Orihara, noted that Orihara's new route that was introduced in Chaos;Head Noah was likely the cause behind the game receiving an 18+ Z rating from CERO.

Release history
Chaos;Head had two demo releases prior to its final product release. The first version of the demo was released on March 21, 2008 which included the first chapter of the game. The second version of the demo was released on April 11, 2008. This second version included the first chapter of the game like the first version as well as a separate "Chapter 1 Reflection Meeting" (第1章反省会) which included all of the main characters trying to determine who the main heroine of the game was. The full game was released on April 25, 2008. Pre-orders of the game came with two bonuses. The first was a patch that added a "Lingerie Conversion System" that swapped the lead female characters' models with models that only wore undergarments and the second was a telephone card. A consumer console port, named Chaos;Head Noah, to be published by 5pb. Games for the Xbox 360 was released on February 26, 2009. The port contains new routes for the heroines' of the game as well as new CG graphics. The CGs are rendered at a resolution of 1280x720, improving on the PC version's scaling of 800x600.

Internet radio show
An Internet radio show named Chaos;Head Radio Delusional Radio Channel (Chaos;Head ラジオ 妄想電波局) began airing on March 28, 2008 to help promote the visual novel. The show was hosted by Hiroyuki Yoshino and Eri Kitamura who voiced Takumi Nishijō and Rimi Sakihata respectively. Other voice actors from the game like Hitomi Nabatame and Chiaki Takahashi also appeared on the show on select episodes. The show was streamed online every Friday and lasted for ten episodes with the last episode airing on May 30, 2008. A soundtrack named Chaos;Head Radio CD Delusional Radio Channel (Chaos;Head ラジオ 妄想電波局) containing two CDs was released on August 29, 2008. The first CD contained all ten episodes of the Internet radio show and an eleventh show titled "Chaos;Head Radio Evaluation Meeting" (Chaos;Head ラジオ 妄想反省会). All eleven tracks are in MP3 format. The second CD is in regular audio format containing "Blood Tune The Radio" (ブラッドチューン The Radio) and "Takumi Nishijō's Everyday Life" (西條拓巳の日常).

Manga
A manga series based on the visual novel, illustrated by Sumihey, has started its serialization in ASCII Media Works' shōnen manga magazine Dengeki Daioh on May 21, 2008. A second manga adaptation, named Chaos;Head -Blue Complex-, revolving around Sena Aoi and Kozue Orihara began serialization in Media Factory's seinen manga magazine Monthly Comic Alive on August 26, 2008. The illustrations are provided by Nagako Sakaki. A third adaptation entitled Chaos;Head H (かおすへっどH) began serializing on September 23, 2008 in Jive's Comic Rush magazine.

Anime
An anime adaptation of the visual novel has been announced and began airing in October 2008. The anime adaptation features the exact same cast of voice actors from the PC game. At Anime Central 2010, North American anime distributor Funimation Entertainment announced that they have acquired Chaos;Head.

The opening theme song, entitled "F.D.D.", will be sung by Kanako Itō and the ending theme, entitled "Super Special", will be sung by Seira Kagami.

The CD single for "F.D.D." (with additional song "Fly to the sky", both in original and off vocal versions) was released on October 29, 2008. The CD single for "First Sight" (with original and exclusive edits), which included the ending theme "Super Special" as its B-side, was released on November 21, 2008.

Also the CD single "Phantasm. FES cv. Yui Sakakibara" was released and contained "Haritsuke no Misa" and "Harukanaru idei yona" songs (both in original and off vocal versions), which can be heard in Episode 3 on Phantasm club performance (end of "Harukanaru idei yona", first couplet of "Haritsuke no Misa" and begin of "Harukanaru idei yona").

Music
Both of Chaos;Head's opening theme, "Find the Blue", and ending theme, "Desire Blue Sky", are performed by Kanako Itō. The CD single was released on May 7, 2008. The single was able to stay on the Oricon charts for three weeks with a peak position of 54th place. A single for the game's insert song, "Zaika ni Keiyaku no Chi o" (罪過に契約の血を), and third ending theme, Gurajiōru (グラジオール), performed by Yui Sakakibara was released on June 25, 2008. Sakakibara's single peaked at 63rd place on Oricon and stayed there for two weeks. The soundtrack for the game was released on July 4, 2008 in a two CD set with seventeen tracks each. The soundtrack's second CD included the second ending theme, "Cry" (クライ), sung by Kanako Itō.

Reception
During the month of March 2008, one month before Chaos;Head's release on April 25, 2008, Chaos;Head ranked fourth in national PC game pre-orders in Japan. Chaos;Head came out in third place in sales ranking in April and twenty-nine for May 2008. Chaos;Head became the 16th bestselling visual novel on Getchu.com during the first half of 2008 and 35th overall for the year of 2008. Chaos;Head Noah placed 11th during its first week of release selling 17,952 copies.