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. At, a port to and , alongside its sequel, Digimon Story: Cyber Sleuth - Hacker's Memory, was announced for October 18, 2019, as Digimon Story: Cyber Sleuth Complete Edition.

The localization retains the Japanese audio track and does not feature an English dub. Cyber Sleuth was followed up two years later with Digimon Story: Cyber Sleuth - Hacker's Memory, a midquel, the story taking place at the same time as the original.

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 travelling 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 Aiba to digivolve/degenerate their Digimon. Aiba can also store Digimon in the Digi-Bank, or send them to one of five Digi-Farms. Mirei Mikagura owns the Digi-Lab and allows Aiba to access it. The Digi-Lab also features a store, which sells Farm Goods, Mirror Dungeons - which allow access to one time only dungeons that have already been completed and counter that allows Aiba to battle Aibas from alternate universes.

Digi-Farm: A feature inside the Digi-Lab. By using Farm Expansion kits, Aiba can get up to five Digi-Farms, which can store ten Digimon each. The Digimon on the farm can be fed various foods, all of which boost stats. The food can either be bought in the Digi-Lab, is rewarded through missions or is found in chests in various dungeons. By using Farm Development kits, Aiba can add up to five Farm Goods, which when training boost stats of the Digimon in the farm. In addition to the stats provided by the farm goods, the farm leader's personality will also boost the Digimon's stats, though unlike previous Story games - these bonus stats are tied to the ABI stat. If wanting to lower any of these stats, Aiba can purchase restraint chips, which will lower bonus stats from training. Aiba can set the Digimon to train which will increase stats, based on the ABI, farm goods and leader personality. Digimon can train for either 30 minutes, 60 minutes or 120 minutes. Choosing the quicker options yields results faster but will lower the CAM stat. In addition, Digimon can also be sent to develop items, or find repeatable farm cases, with the same 30/60/120 minute options.

Digivolve: Here, Aiba can digivolve or de-digivolve their Digimon. The requirements to digivolve to a higher form are identical no matter the lower form, whilst the requirements to de-digivolve to a lower form are: "You have discovered this Digimon before". If the Digimon has not been recorded in their Field Guide, they cannot De-Digivolve into a lower form but can digivolve into higher forms they have yet to see, provided they meet all the requirements. Once a Digimon digivolves or de-digivolves, their level will reset to level 1, however their ABI and maximum level will increase. Digimon stats are fixed and will never change, so a level 50 Agumon will always have the same stats as every other level 50 Agumon, the only customisation being the use of bonus stats, tied to the ABI stat and the personality, which boosts a one stats by 5%. There are some Digimon, that even at level 99, will be unable to digivolve into some of their higher forms, meaning the Digimon must be trained to reach the required stats. A Digimon can only have a maximum of 20 moves, meaning moves will need to be delete should a Digimon learn a 21st attack.

The personalities are as follows:


 * Durable: Increases HP.
 * Lively: Increases SP.
 * Fighter: Increases ATK.
 * Defender: Increases DEF.
 * Brainy: Increases INT.
 * Nimble: Increases SPD.
 * Builder: Provides faster and better quality returns on Item Development.
 * Searcher: Provide faster and better quality returns on Investigations.

Aiba can purchase patches in EDEN to change a Digimon's personality.

The stats are as follows:


 * HP: The amount of HP the Digimon has. When a Digimon's HP reaches 0, they cannot battle any more.
 * SP: The amount of SP the Digimon has. Every attack, other than the generic attack, takes a certain amount of SP, which is taken from the overall SP. If the Digimon does not have enough SP, it cannot use the move.
 * ATK: The damage of Psychical Attacks is based on how high the ATK stat if the attacking Digimon is.
 * DEF: The damage of Psychical Attacks is based on how high the DEF stat of the defending Digimon is.
 * INT: The damage of Magic Attacks is based on how high the INT stat is of the attacking Digimon is and how high the INT stat is of the defending Digimon. INT also effects how much HP is healed when using healing attacks.
 * SPD: The turn order is decided in order of each Digimon's SPD stats. The higher the SPD is compared to the other Digimon, the more turns the Digimon will get. If the SPD stat is high enough, Digimon can get multiple turns in a row.
 * CAM: CAM maxes out at 100. The higher the CAM of a Digimon is, the more likely they are to do Cross Combos. Cross Combos have Digimon teaming up to do their special attack, taking only SP from the commanding Digimon. Digimon must be next to each other in the attack list to do Cross Combos. CAM increase by 1 each time a Digimon is in the active party at the end of a battle.
 * ABI: ABI maxes out at 100. The higher the ABI, the more bonus stats can be trained, with the amount being equal to 50+half the ABI stat, maxing out at 100. ABI is increased by Digivolving and De-Digivolving, though some food also increase the ABI stat.

Digimon Capture: Every time Aiba fights wild Digimon in battle (not including boss fights), the program will scan all the Digimon's data. The higher levelled the Digimon, the less data it scans. When reaching 100% scan, Aiba can create their own version of the Digimon. Unlike previous Story games, which max out at 999%, Cyber Sleuth scan data maxes out at 200%. Creating a Digimon with more than 100% scan data will cause the Digimon to start with a higher ABI, starting at 0 ABI at 100% scan, and 5 ABI at 200%. Aiba can also return Digimon to 100% scan data, as well as load Digimon into other Digimon, permanently deleting them, turning them into experience points for the Digimon absorbing the Deleted Digimon.

Memory: Aiba is allowed to store up to 11 Digimon in their Digi-vice at once, with three acting in the battle slots. Memory acts as a capacity limitation, with more powerful Digimon taking up more memory. As an example, should Aiba have 20 memory, they could store 10 Training I Digimon in their digivice, who all take 2 memory or take a lower amount of Digimon of higher levels, such as four 5 memory Rookie level Digimon. Memory can increased by using Memory Ups and Memory UP DX, which add 5 and 10 memory respectively, which can be found in chests, drop from boss fights or are rewards from completing missions.

Battle System:. Like previous Story games, battles are random encounters and allow fights against up to 3 Digimon. The 3 Digimon n the active party slots will be used in battle, though should Aiba have less than three Digimon, one/two will be used. Aiba can also willingly used less than three Digimon by only assigning one or two Digimon to the active party slots. Battles are turn based, with the attack order being based on the SPD of the Digimon in battle. Aiba can do the following commands:


 * Attack: The chosen Digimon will do a generic attack, that takes no SP.
 * Skill: The chosen Digimon will do the chosen attack, provided the Digimon has enough SP.
 * Guard: The chosen Digimon will take no action and will instead guard, which will half the damage of any attacks that hit them until their next turn.
 * Item: Aiba can use an item.
 * Escape: Aiba and their Digimon will escape the battle. Some battles cannot be escaped from.
 * Change: Aiba can switch out any of the active battle Digimon, with any of the reserve Digimon, including Digimon with no HP, the switch taking the turn of the Digimon who's turn was used to do the switch. The turn order will change based on the SPD stats of the new Digimon and continue as normal.
 * Auto: The battle speeds up and the Digimon choose their attacks on their own. Commands cannot be used during Auto mode.

Attributes:
 * Fire: Strong against Plant, weak against Water.
 * Plant: Strong against Water, weak against Fire.
 * Water: Strong against Fire, weak against Plant.
 * Electric: Strong against Wind, weak against Earth.
 * Wind: Strong against Earth, weak against Electric.
 * Earth: Strong against Electric, weak against Wind.
 * Light: Strong against Dark, weak against Dark.
 * Dark: Strong against Light, weak against Light.
 * Neutral: Strong against and weak against nothing.

Types
 * Vaccine: Strong against Virus, weak against and does half damage to Data
 * Data: Strong against Vaccine and weak against and does half damage to Virus.
 * Virus: Strong against Data and weak against and does half damage to Vaccine.
 * Free: Strong against and weak against nothing.

A double advantage can be reached if a Digimon with a Type advantage uses a move with a Attribute advantage over another Digimon. The opposite happens if a Digimon with a Type disadvantage uses a move with an attribute disadvantage. For example, A Vaccine Digimon using a Fire Attribute attack will do x3 damage against a Digimon that is Virus/Plant, whilst using the same move against a Data type will do x0.5 damage. A Vaccine Digimon can boost their damage to 0.75% if they attack a Data Digimon with a move that is strong against the Data Digimon's Attribute, such as using a Fire Attribute attack against a Data/Plant Digimon. A Digimon attacking another Digimon with a Attribute Advantage will do x2 damage, or x1.25 if both Digimon are the same type, or if the Digimon is Free type.

List of Obtainable Digimon
Cyber Sleuth includes 249 Digimon. This includes pre-order exclusive Digimon, which outside of Europe, could only be obtained by pre-ordering the game, or buying a new copy. The Field Guide shows the Digimon's model, can show attack and walking animations, like previous Story games, shows stats for any level between 1 and 99, with the default being level 1, shows the attacks each Digimon can learn, shows their Digivolution trees and has a profile for each Digimon in the game.

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. By May 2019, Cyber Sleuth had sold over 800,000 copies worldwide.

Preview
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