AI: The Somnium Files Wiki
AI: The Somnium Files Wiki

Kuruto Ryuki (龍木 来斗, Ryūki Kurūto) is the second protagonist of AI: THE SOMNIUM FILES - nirvanA Initiative.

Kuruto is ABIS's new Special Agent (Psyncer), and a rookie investigator with a strong sense of justice. However, he is not the hot-blooded type; he has a reserved and gentle nature. He is a well-educated young man. Unfortunately, both his parents and his brother have passed away... Fighting through his painful past, he aims to solve difficult cases with his partner, Tama, who is implanted in his left eye socket.


Ryuki is a young man with somewhat unkempt black hair and two different eye colors—his right eye is gray, while his left is red thanks to his artificial eyeball Tama. Ryuki wears a black double-breasted jacket with a small flower pin on the right lapel. Underneath, he wears a long sleeved white collared shirt with the top button undone, a plain black tie, and a ribbed knit orange sweater with thumb holes in the sleeves. He also wears black slacks, and white shoes with orange bands around the bottom.


Ryuki something of an honor-student. He is largely defined by his dedication to his eagerness to prove himself to his superiors, particularly Boss and Date, and ties his self-worth on their approval, He is especially close to Date and the two share a close "physical" and emotional relationship according to Date, with Date acting as a major source of moral support for Ryuki. His strong sense of justice stems from a strong hatred of criminals, and is shown to be extremely determined to do his job. When faced with failure, Ryuki tends to blame himself, and doesn't easily accept words of comfort when he's feeling down on himself.

Unlike Date, who is prone to outbursts of perverted behavior (although Ryuki is not impervious to having sexual thoughts), and unlike Mizuki who is regularly crass and rude, Ryuki is generally very polite, professional, and straight laced. He regularly acts as a straight man to the antics of others, especially to Tama when she teases or bosses Ryuki around, or when she makes dirty jokes. Despite this, he does appear to share Date's affinity with being tied up, particularly by Tama. However, he strangely doesn't find the activity sexual and finds it relaxing instead. He is also not above having his own outbursts of silliness, and occasionally does Half-Might impressions to cheer himself up (although this tends to make the people around him confused and concerned for his well-being). During Somnia, he takes on a more commanding and confident persona and is shown to be a bit bossier with Tama, a reversal of their usual dynamic. Regardless of his circumstances however, he regularly shows a strong desire to protect those close to him, and is willing to take drastic measures to ensure their safety.

Another of Ryuki's defining traits is his difficulties with mental health. Although generally calm and collected, he is shown to suffer some form of survivor's guilt and PTSD; although he tries to channel his grief into determination for his investigative work, he generally does not handle emotional stress well, and is prone to bouts of depression, obsession, deep self doubt, and self-blame. His struggles initially stemmed from the traumatic loss of his twin brother in a traffic accident in pursuit of a criminal, and his dislike of stopped clocks, and his hatred of criminals originates from the same event. Additionally, as his symptoms appear to worsen as a result of more traumatic events that occurred during the events of the original Half Body Killing investigations, he becomes prone to dissociation, memory lapses, hallucinations, derealization, and even mania. He also appears to be strangely susceptible to the videos tied to the HB-Case, as they seem to trigger his dissociative episodes and hallucinations. All this, in combination with his struggle to accept forgiveness from other people, lead him to spiral easily, and give him the appearance of being self-destructive and even dangerous. However, deep down he is merely a vulnerable person who deeply struggles with guilt and self-worth, and seeks atonement for his mistakes, but doesn't believe he is deserving of it. With the support of others, he is ultimately able to find the will to pull himself out his depression and start to recover.



Kuruto Ryuki was born on October 18, 1996 to his parents as an older twin to his brother. Ryuki grew up both rich and highly educated until his parents were killed in a plane crash. He was living with his younger brother until his death in 2014 when he was hit by a truck and half of his body was utterly crushed.

By the age of 21, Ryuki graduated from college and inherited his brother's dream of becoming a police officer. By 23, he had already become an accomplished agent at ABIS under the tutelage of Kaname Date, whom Ryuki very much looked up to.


On February 10, 2020, Ryuki was a contestant on a quiz show filmed at Studio Dvaita. However mid-show, the lights temporarily cut out and a corpse suddenly appears on the floor. This was the beginning of what ABIS called the Half Body Serial Killings. After attempting to investigate the right-half of who was obviously Jin Furue, the body combusts in flames, with Ryuki's investigation later confirming it did so using the thermite inside the corpse.

On February 11, 2020, Ryuki heads to Naixatloz Japan and questions their president Tokiko Shigure over the discovery of Jin's body at the studio. Tokiko also asks Ryuki if he was the "frayer", before denying any connection Naix had to the QR video from the studio.


Ryuki Diverge Route

On February 11, 2020, Ryuki heads to Naix and questions Tokiko. Tokiko also asks Ryuki if he was the "frayer", which allows Ryuki to enter the "Nil Number" both Mizuki and Bibi received on February 22, 2026. However by doing so, the world began to "glitch", causing unexplainable things to occur around him. Mamoru is in a T-pose with half of his face not rendered, as well as Tokiko's right-half appearing on her desk as it was supposed to look like in 2026.

Tama is offline, and Ryuki hears Tokiko's voice asking him to meet her. He walks through the geometrical area and into the empty black area where he meets Tokiko covered in a blazing red aura. Tokiko began questioning Ryuki as to how it was possible he knew the number. Confirming this to be a "logical paradox", she explains that what Naix believed about the world was true, and that her motive for threatening Amame and committing suicide was all meant to lead the "frayer" to this moment. She offers the frayer an opportunity to tell Ryuki all the details about the case that they have learned before leaving and ascending to Mohska. Ryuki and Tama black out, and their actions are entirely controlled by the "frayer".

In the perspective of Ryuki and Tama, they awaken immediately after Tokiko's ascendence but find that six years have passed since. Tokiko has been classified as missing since. According to Date, Ryuki discovered Tearer's basement underground of Horadori and arrested Uru on the spot. This would ultimately result in Ryuki being promoted to second-in-command of ABIS. The explosion never occurred, Date never lost his memories again, Kizuna did not lose the use of her legs, and Amame had no reason to kill Uru because Komeji was alive in this timeline.




  • Ryuki (龍木) is derived from the Japanese spelling of Nāgārjuna (龍樹), the name of a Buddhist philosopher. The first kanji means "dragon" and the second means "wood" or "tree." Nāgārjuna was known, among many things, for his contributions to the two truths doctrine, which states that there are two truths to reality: the conventional truth of the material world, and the ultimate truth of the emptiness of everything.
  • Ryuki is a play on "rookie."
  • Kuruto is a play on "recruit," as well as 狂う人 (kurū hito), meaning "madman" or "crazy person."


  • Some fans have noted that Ryuki bears a resemblance to the character Shinya Kogami from the anime series Psycho-Pass, who also works as a police officer at a special sci-fi division of the police.[1] However, series creator Kotaro Uchikoshi stated that it was simply a coincidence, and that Ryuki's personality is the complete opposite to Kogami.[2]
  • Ryuki's impressions of Half-Might are an obvious nod to All-Might from My Hero Academia. In the original Japanese script, they were references to Anpanman, but was switched to something that English-speaking audiences might be more immediately familiar with.


AI: THE SOMNIUM FILES - nirvanA Initiative
Protagonists: Mizuki DateAibaKuruto RyukiTama

Main Characters: Iris SaganKizuna ChiedaAndes KomejiAmame DoiGen IshiyaganeShoma EndaLien TwiningKaname DateMasked WomanTearer
Supporting Characters: Chikara HoradoriTokiko ShigureBossPewterOta MatsushitaHitomi SaganMoma KumakuraMama
Minor Characters: Jin FurueRiichi ChiedaSo SejimaAraya KagamiMikoto UshideraChinpei WagaiDokuta YoganoRitsuko EnshuMamoru BodaiHanayo NasuTakushi IbaradoMarco


Chiyoda District: Police Headquarters (Boss's Office, Psync Room, Interrogation Room) • Sunfish Pocket
Chuo District: Horadori Institute of GeneticsNaixatloz Japan Branch
Koto District: Harbor Warehouse DistrictDate Residence
Minato District: Studio DvaitaAioen OrphanageIkume ShrineKumakura OfficeSejima ResidenceCentral Hospital
Shibuya District: Lemniscate Entertainment OfficesYoyagi Park
Shinagawa/Kabasaki District: Matsushita DinerSagan ResidenceEnda ResidenceKabasaki Chemical Plant
Shinjuku District: Golden Yokocho (Marble, Brahman World Cuisine) • Sekiba HighTokyo National Stadium

New InvestigationNefarious InstituteNaixatloz's IntentionsNeed InfoNested InsecuritesNearly InterestingNemesis IdentifiedNostalgic IdolNecessary InterventionNeurotic InceptionNonentity IncognitoNovel IngressNightmare Irreconcilable
Converge Chapter: A Strange Tale

Side Ryuki:
DispossessedAnyone ImaginesOught to KnowNothing to Be DoneGoFarewell
Komeji and Shoma Route: Joy for AnguishI Found MePast Its Ken
Explosion Route: Smiles for TearsWell-KnownThe Mind of GodNot All A DreamShe Was the Universe
閭陜カ荵句邱ィ Route: 遐エ邯サ逋セ蜃コAll This Happened, More or Less
Side Mizuki:
AlonePass Mildly AwayEnd Where I BegunTravelerLeft BehindThe Expense of Spirit
Gen and Amame Route: All Living ThingsOf Arms and Of ManWho's ThereAll That We Are
Kizuna and Lien Route: Bid the Soldiers ShootSweet Silent Thought
Resolution Route: HellVisionsIn TruthBirthsThe End of CravingBraver Than All Flowers

Tokyo Metropolitan Police Department (Advanced Brain Investigation Squad) • AMABIE-TVChieda FamilyHoradori Institute of GeneticsNaixatlozOrder of %
Psync MachineWadjet System • Mizuki's enhanced pipe • EvolverEvolver MC
Bats490Fray to FreeNirvana TrialNirvana X
Mizuki's ScooterRyuki's Limousine
Half Body Serial KillingsNirvana Initiative
Full List of Events