Digimon Story: Cyber Sleuth

Digimon Story: Cyber Sleuth (デジモンストーリー　サイバースルゥース) is a Digimon video game for the. It is part of the Digimon Adventure 15th Anniversary and an entry in the  series. At, a localized release was announced for 2016 through retail for the and digitally for the PlayStation Vita. The localization retains the Japanese audio track and does not feature an English dub.

Plot
While Aiba is hanging out in a chatroom, a hacker infiltrates it and leaves a message telling the members within to log into Cyberspace EDEN, a popular physical-interaction cyberspace network, to receive a "wonderful present". Although most of the room members declare it to be too suspicious to involve in, Aiba, along with users "Akkino" and "Blue Box" decide to look into it. Aiba meets them the next day as arranged in, a hacker-infested area of EDEN, where they introduce themselves as Nokia Shiramine and Arata Sanada; shortly after, the three of them are given the "Digimon Capture" by the unknown hacker and locked into Kowloon. While searching for an exit, Aiba runs into a hacker named Yuugo, the leader of hacker team Zaxon who resembles a rumored "white boy ghost" said to have been sighted around EDEN, who teaches them how to use their Digimon Capture and reveals that Arata is in fact a skilled hacker. Shortly afterwards, Aiba, Nokia, and Arata run into a mysterious creature that attacks them, and although Arata manages to hack open a way out for them, the creature grabs onto Aiba's leg and corrupts their logout process.

Aiba emerges in the real world as a half-digitized entity and is rescued by a detective named Kyoko Kuremi, who specializes in cyber crimes and offers to take them into her service as her assistant. Aiba manifests an ability called Connect Jump, which allows them to travel into and through networks.

The game thereafter splits into three different simultaneous plotlines:


 * Aiba helps Nokia reunite with an and  she'd met and bonded with in Kowloon; she learns from them that Digimon are not hacker programs (as the public believes them to be) but living beings that come from a "Digital World", and that Agumon and Gabumon came to EDEN for a specific purpose that they can't remember. Nokia vows to help them recover their memories, but soon after begins to flee from confrontations with dangerous hackers; after being soundly defeated by Zaxon team hacker Fei Wong Tomoe Ignacio, she decides to become stronger and form her own hacker group, the Rebels, for the sake of improving relations between humans and Digimon. Her hard work allows Agumon and Gabumon to digivolve into WarGreymon and MetalGarurumon and sheer positivity ends up gaining her a large number of followers, causing Yuugo to worry that she might interfere with his goals of protecting EDEN and its hackers.
 * Arata, who remains evasive about his own past as a hacker, assists Aiba in investigating "Digital Shift" phenomena around Tokyo, in which areas become mysteriously half-digitized. They meet a scientist named Akemi Suedou who identifies the mysterious creature as an "Eater", a corrupted mass of data that is responsible for digitizing areas and causing human victims to fall into a comatose state called "EDEN Syndrome" by "eating" its mental data. Further encounters with Eater signify that it has links to the "white boy ghost" that keeps appearing around it, and that by "eating" data it can evolve into different forms. After Arata learns the truth about Aiba's condition and witnesses a number of acquaintances become victims of EDEN Syndrome, he resolves to do whatever he can to save them.
 * Yuuko Kamishiro, the daughter of the former president of Kamishiro Enterprises (the company that manages EDEN), requests Kyoko's detective agency to investigate her father's purported suicide and assists them in infiltrating the company when needed. Investigations via hacking into Kamishiro Enterprises areas reveal that the company's current president, Rie Kishibe, is planning a large EDEN update that ties into something called the "Paradise Lost Plan". Along the way, Aiba learns that Yuuko's older brother is in fact a victim of EDEN Syndrome.

Eventually, Yuugo mobilizes hackers around EDEN to attempt a large-scale hacking on Kamishiro Enterprises's high-security Valhalla Server for an unclear purpose. Arata attempts to intervene, revealing that he was in fact the leader of a top-class hacker group named Jude that dissolved due to a traumatic event that occurred during a previous Valhalla Server hacking attempt. Nokia, during a moment of determination, accidentally causes WarGreymon and MetalGarurumon to DNA Digivolve into Omnimon, but everything is quickly brought to a halt when Rie arrives and unleashes a large crowd of Eaters on the hackers, revealing that the entire setup was a trap to get Yuugo to accumulate Eater prey. While Omnimon puts a stop to the Eater rampage, Rie forcibly logs out Yuugo, who turns out to in actuality be Yuuko using a false EDEN avatar modeled after her older brother. Rie informs Yuuko that she'd imbued the avatar with an artificial personality that she had used to manipulate Yuko's actions, and begins a process of extracting Yuuko's memories.

Omnimon's restoration to his form causes him to remember that his true purpose of coming to EDEN was to save the Digital World from an infestation of Eaters, which were created from negative human emotions taking form in EDEN. The Digital World's ruler,, had determined that humans were the cause, and its were split in deciding whether or not its will was to destroy humanity to eradicate the Eaters. Deducing that Rie's plan is to open a dimensional door to allow the Royal Knights in, Aiba and their friends chase after her in order to stop her and save Yuuko, but due to the interference of Suedou, who reveals that he was the one who had handed out the Digimon Capture, they fail to stop her from opening the gate and revealing herself to be the Royal Knight. The group then attempts to save Yuuko, who has been absorbed by Eater into an entity called, but even after defeating it Yuuko refuses to emerge from her despair at being manipulated. Aiba, realizing that Eater is digital and they can Connect Jump into it. With the help of Fei's, they convince Yuuko that she's not alone and get her out, but Aiba is pulled into a digital void; there, they meet the real Yuugo Kamishiro, Yuuko's brother and a victim of Eater. He wishes Aiba and their friends well before asking them not to search for him and a mysterious Digimon rescues them.

Aiba returns to the real world to discover that weeks have passed and the opened dimensional portal has caused the entire world to become a giant Digital Shift and that Digimon are running amok in the real world. The group begins to search for the other Royal Knights in the hopes of convincing them to join their sides instead of trying to destroy humanity. In the process, Aiba and Yuuko discover from Makoto Yamashina, a former member of Kamishiro Enterprises, that eight years prior there had been an EDEN beta test eight years prior involving five children; one of them, Yuugo, had become the first EDEN Syndrome victim, while the other four had their memories of the incident wiped by Suedou and the incident was covered up. Shortly after, Suedou sparks a certain memory back in Arata, which causes him to gain an obsession with becoming stronger and leave with him.

Aiba and their friends eventually manage to recruit most of the Royal Knights through various means; in the meantime, Arata partially merges with Eater and begins to rampage around town by "eating" data. A confrontation reveals that Crusadermon was in fact responsible for the murder of Yuuko's father, and that the five children from the EDEN beta test were in fact none other than Yuugo, Yuuko, Arata, Nokia, and Aiba, sending them into a recreation of the events of how they found a hole in EDEN, made first contact with the Digital World, and accidentally led Eater into it, thus accidentally instigating the Eater infestation. In order to save them as Crusadermon attacks, Kyoko arrives and reveals her true form as Alphamon, the thirteenth Royal Knight; after Crusadermon's defeat, Kyoko reveals that she and Rie are in fact former humans whose minds were victims of Eater and had their bodies possessed by Alphamon and Crusadermon, and that their own personalities have received slight influences from their human mediums.

As Aiba and company head to the Tokyo Metropolitan Office to stop, the leader of the Royal Knights' human genocide plan, Arata, mired completely despair over having let Yuugo become an Eater victim and forgotten his own best friend, transforms completely into an Eater, but Aiba manages to save him with Connect Jump in the same way they saved Yuuko. After stopping Leopardmon, Suedou tells the group that they can stop Eater by traveling to its core in the Digital World and extracting Yuugo from it, which will make it so that Eater and EDEN Syndrome never existed. The group arrives to find King Drasil having been taken over completely by Eater into an entity called the Mother Eater; after defeating it, Aiba Connect Jumps in and extracts Yuugo, who refuses to be saved and reveals that, because he had been acting as a limiter on Eater's actions, without him as a central conscience it has no restraint to simply eat everything indiscriminately.

Suedou takes the opportunity to merge with Mother Eater and become its new conscience, hoping to recreate the world and make it evolve into a world without misery, forcing the others to band together and defeat him. Despite knowing that continually Connect Jumping into Eater will take a toll on their body, Aiba does so anyway in the hopes of rescuing Suedou. Suedou, amazed that Aiba would attempt to save someone like him and claiming that such a thing is outside King Drasil's calculations, decides to have faith that the future isn't fated to end in sadness and sends Aiba away so that he can reboot King Drasil and disappear with Eater.

As Aiba returns to their friends and watches the reforming Digital World, King Drasil performs a restoration on it, meaning that the humans will have to return to their own world, the Digital World will be returned to the state it was in eight years prior, and the world will be reverted to a state in which contact with the Digimon never happened. Alphamon and the other Digimon bid farewell under the promise to meet again, and Aiba accompanies their friends back to the human world, but on the way back they dissolve into data before their friends' eyes.

In the real world, with its status changed so that Digimon contact never happened, only Nokia, Arata, Yuugo, and Yuuko remember the events while Aiba is still comatose; Yuuko's father is alive again, while Rie is a normal human woman, and Suedou was made to have never been born. Eventually, Aiba's scrap data is found by Alphamon, who has their Digimon team gather data from their memories of them to recreate their mind and restore them to their body. After being restored, Aiba meets Kyoko, who has no memory of the incident or of them, but invites them to work as her assistant.

Development
The game features CG cutscenes made by. German subtitles were added in a free patch on September 15, 2017.

Gameplay
Digi-Lab: Allows player to digivolve and assign or store his/her Digimon, with Mirei Mikagura as assistant.

Digi-Farm: A feature inside Digi-Lab. Allows player to train Digimon or search some items.

Digivolve: A Digimon can digivolve or even degenerate/de-evolve by fulfilling its requirements (mainly level and stats). One Digimon can digivolve to various Digimon with different requirements. Digivolution can only be done in Digi-Lab. Once a Digimon digivolves to higher level, their level will reset to level 1 but will get better stats and techs. With the exception the starter Digimon, a Digimon evolution tree starts at Baby level.

The challenge for the player is a possible evolution of a Digimon that is hidden by silhouette if the player never owned that Digimon. Player need to guess the Digimon's silhouette or simply by trial-error and save the game to figure out the Digivolution results.

Degenerate a Digimon to lower level allows the Digimon to get better stats growth when it re-digivolve to same Digimon. This sometimes needed to unlock some Mega levels to get the stats requirements.

Digimon Capture/Scan: At the start player will choose between three starter Digimon: Terriermon, Palmon, or Hagurumon. After that, every time player meets wild Digimon in battle (not included boss/forced fights), the player will scan all  the Digimon's data. With multiple battles against the same Digimon, it will eventually reach 100% scan (capped at 200%, higher % possibly for better stats) and the Digimon will be allowed to be summoned from Digi-Lab and become allies. The Digimon then can be taken care of by player (Digivolve etc)

Digi-Memory: The Player is allowed to bring up to 11 Digimon at once to the field (although only 3 assigned for battles), with Digi-Memory as capacity limitations. The memory numbers are dependent on the Digimon's evolution level (higher level, higher points). The Digi-Memory can be increased/upgraded as the story progresses.

As an example, players with 20 memory points can bring up to 10 Baby Digimon with 2 points each (2*10 = 20) but can only bring 4 Baby and 3 Rookie with 4 points each (4*2 + 3*4 = 20).

Battle System: Unlike forced/boss battles, the battle triggers randomly on the map (similar to Digimon World 3). 3 Digimon will be active in battle but can be changed during battle. Players have the main commands as follows; Attack, Skill, Guard, Item, Escape, Change, and Auto. The battle system for this game has a lot similarities to CTB (conditional turn based) from Final Fantasy X

Element Systems (Fire, Plant, Water, Electric, Wind, Earth, Light, Dark and Neutral) and Type advantages (Vaccine, Data, vs Virus) also apply in battles.

Additionally, during battles a game over will occur if all Digimon defeated. If 3 Digimon in battle defeated they will be replaced by Digimon in the reserve slots.

Credits

 * Producer: Kazumasa Habu
 * Director: Tetsuya Ookubo
 * Composer: Masafumi Takada
 * Creature design: Oh!Great
 * CG scenes:
 * Digimon design: Kenji Watanabe

Reception
The  magazine named Cyber Sleuth the best game of 2015.

Preview
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