Chaos;Child

Takuru lives in a caravan trailer by Miyashita Park in Shibuya.

Chaos;Child is set in Shibuya in 2015, six years after the events of Chaos;Head, where an earthquake nearly leveled the area.[1][2] Shibuya has since been rebuilt, but a new series of odd killings begin to occur on the same days of the "New Generation" murders, dubbed the "Return of the New Generation Madness" murders and marked by stickers of a two-faced man called "Sumo Stickers" left at the crime scenes.[3] Several characters have awakened to psychic abilities in the wake of the earthquake, such as pyrokinesis or being able to spot lies with absolute certainty;[1][3] such individuals are referred to as Gigalomaniacs, and use their abilities by making delusions come true in the real world ("real-booting") through the manifestation of a Di-Sword, which connects them to the Dirac sea.[3]

The story follows a group of high school students at Hekiho Academy who survived the earthquake:[1] the player takes the role of Takuru Miyashiro,[1][4] the president of Hekiho's newspaper club, whose family died in the earthquake. Other major characters include the newspaper club members – Takuru's childhood friend Serika Onoe, his foster older sister Nono Kurusu, and Hana Kazuki and Shinji Itou – and Shuichi Wakui, the teacher overseeing the club, and the misanthrope Mio Kunosato who aids the police and works with detective Takeshi Shinjo. Takuru and Nono live with their foster siblings Yui and Yuto Tachibana and their foster father Wataru Sakuma at Aoba Dorm, a combined foster home and medical clinic, although Takuru also stays in a caravan trailer by Miyashita Park.[3]

In 2015, six years after the New Generation serial killings and the Shibuya Earthquake, high schooler Takuru Miyashiro is searching for a story to cover for his school's newspaper club. After looking into the cases of two recent deaths, Takuru notices that the killings are mimicking the New Generation Killings from six years ago and are occurring on the same dates.

Despite the objections of his foster sister Nono Kurusu, Takuru and the rest of the newspaper club, including childhood friend Serika Onoe, Shinji Itou, and Hana Kazuki, begin to investigate the killings with the goal of exposing the culprit themselves. Along the way, Takuru meets characters such as Literature Club member Hinae Arimura, the cold and calculating Mio Kunosato, detective Shinjo Takeshi, and young Uki Yamazoe.

Mio reveals the existence of Gigalomaniacs, people who have the ability to manifest delusions into reality. After meeting with Hinae, who is also a Gigalomaniac, Mio and Hinae deduce that Takuru must be a gigalomanic with the ability of telekinesis.

Hinae and Takuru are attacked by a pyrokinetic Gigalomaniac, assumed to be Senri Minamisawa, an old friend of Nono's who presumably died in the earthquake. Takuru remembers back to his childhood, where he found Senri being experimented on while exploring the hospital. He assumes that Senri is upset that Takuru never stopped to help her, and is attacking him in revenge.

Shinji murders Takuru's younger foster sister Yui, claiming that he was in love with Senri and wanted to exact revenge on Takuru for abandoning her at the hospital. When Nono proves it was impossible for Shinji and Senri to have met in the past, Shinji has a mental breakdown and collapses.

Nono soon finds evidence to implicate Serika. She confronts Serika on the school rooftop, where they reveal themselves as Gigalomaniacs and fight each other. Takuru arrives shortly after, to witness Nono killed as a result of the fight. Takuru is officially implicated for the murders with the news widely spreading across Shibuya.

It is revealed that Serika was actually Takuru's imaginary friend, who he booted into reality when he awoke as a Gigalomaniac. Serika reveals she is working with Sakuma Wataru, Takuru's foster father, to orchestrate the killings.

Sakuma, who has rebuilt an artificial Gigalomaniac device from the wreckage of Noah II, fights with Takuru, revealing that his motivation was simply to have fun torturing and experimenting on Gigalomaniacs. Takuru wins the fight, killing Sakuma. Serika soon shows up and reveals that she was created with a purpose: to give Takuru something to do, and help him do it. As Takuru was a fan of the original New Generation killings, Serika orchestrated the copycat killings to have Takuru solve it, and become a hero in the process. Refusing to let his original wish play out, Takuru uses his powers to wipe Serika's memory and free her from his wish. Takuru is later arrested for the murders.

Character routes are unlocked, revealing Hinae's backstory of losing her brother in the earthquake, Kazuki's status as a Gigalomaniac, teacher and club advisor Wakui Shuuichi as a member of the Committee of 300, and Nono as the real Senri Minamisawa.

After the Character routes are completed, the True End is revealed. Serika wakes up three months later, with little memory of who she was before. She finds herself drawn to Shibuya, where she meets Mio, Shinjo, and Takuru. Mio introduces her to Chaos Child Syndrome, in which its affected are trapped in a synchronized delusion, causing rapid aging in the process. They travel to a facility underneath the school, where they free everyone from the syndrome.

Weeks later, Takuru is to be transferred to a prison. On his way out of the hospital, he encounters Serika. Passing each other, he and Serika both claim that they do not know each other, and they will live their lives apart.

Chaos;Child was localized by Adam Lensenmayer, who previously worked on the localizations of Steins;Gate 0 and of the anime adaptation of Steins;Gate. He was the only translator working on the localization; this was done as he and the developers wanted to ensure consistency in the way each character speaks and in the feeling of the game, as having multiple translators work on a single project can lead to differing interpretations of the story and of characters' personalities. He had not played the game prior to the start of localization, so after finishing his first translation pass of the script, he went through it in full a second time to correct things he had originally misunderstood due to not knowing how the story plays out.[9]

While Lensenmayer described the translation itself as straightforward, due to the Japanese dialogue being easily understandable, he found the game exhausting to work on, giving quality control of the game's opening sequence as an example: he had to keep watching the opening to check text that is only displayed briefly on-screen, and thus had to see a character choking to death many times. The localization was additionally a large project with a script 30–40% larger than Steins;Gate 0's, taking most of the remainder of 2016 to finish following the completion of the Steins;Gate 0 localization. Due to the experience of having worked together with the developers on the localization of Steins;Gate 0, the process was however smoother, with a lot of communication back and forth on how to localize various things. The localization took fan feedback into account: after Lensenmayer had submitted the localized script, he worked on the translation of the Chaos;Child anime adaptation, and read comments about how some translation choices in the anime were inconsistent with their use in Chaos;Head, such as the rendering of a phrase as "Those eyes! Whose eyes?" rather than "Whose eyes are those eyes?!". Contacting the developers, he was able to get most such instances changed in the game script.[9] A fan-made patch containing further consistency fixes with other games in the series, along with translations of some previously untranslated graphics, was released for the Windows version in 2019.[10]

The Xbox One and PlayStation 3 versions of the game were unable to reach the Japanese weekly sales charts upon launch;[25][26] the PlayStation Vita and PlayStation 4 versions did, however, selling 10,325 and 4,860 copies, respectively, with the PlayStation Vita version being the ninth best selling game of the week.[27] On the following week, the PlayStation 4 version had dropped off the chart, while the PlayStation Vita version dropped to seventeenth place with 2,556 additional copies sold.[28] In the United Kingdom, Chaos;Child was the best selling PlayStation Vita game during its European debut week in October 2017,[29] and charted until the end of May 2018;[lower-alpha 1][33][34] the PlayStation 4 version did however not appear at all in the weekly top-twenty PlayStation 4 game sales chart for the region.[35]

By October 2020, the game had only sold approximately 10% the amount of copies as Steins;Gate; this led to the development of Steins;???, a thematic sequel to Steins;Gate that relates to it similarly to how Chaos;Child relates to Chaos;Head.[36]