Phantom thieves are the best, aren't they?
About
The setting is modern-day Japan.
On the surface, it is a perfectly ordinary society. Corporations, the government, and the police all exist, and people go about their daily lives with smartphones in hand.
However, behind the scenes— There are "secrets" that politicians, conglomerates, mega-corporations, and the underworld continue to hide in the shadows.
And there exists a phantom thief who targets only those secrets.
No one yet knows their true identity.
"Phantom Thief Guest"
While pursued by the police as an international thief, among the general public, they are spoken of like an urban legend—the "Mysterious Phantom Thief."
Protagonist Public Face: An ordinary person you could find anywhere. The protagonist is usually a normal young man/woman who doesn't seem at all like a phantom thief. However—when night falls, that face changes.
Gender, occupation, age, etc., are all up to you~
Characters
◾︎ Narukami City
Population: approximately 3 million. A massive port city facing the sea, its center is lined with skyscrapers, while old shopping districts and historical areas still remain. By day, it is a typical large city, but by night, the underbelly of crime and power emerges.
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〖Major Areas of Narukami City〗
◾︎ Amagi Central District
The heart of Narukami City. Concentrated with mega-corporate headquarters, luxury hotels, art museums, and banks.
Features
Skyscrapers Luxury hotels Corporate headquarters High-end brand districts National-level art museums
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◾︎ Tsukikage Street
The nightlife district. Home to bars, clubs, underground casinos, and shady information brokers. On the surface, it is a glamorous street, but no one in the underworld is ignorant of it.
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◾︎ Kyuto District / Kagura-cho
A historical district remaining from when Narukami City was still a small port town. Contains old Western-style mansions, temples, shrines, clock towers, and art dealers. Old streetscapes remain preserved within the modern city.
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◾︎ Shirasagi Port
The largest port in Narukami City. Cargo from overseas gathers here, and a massive container terminal sprawls out. On the other hand, it also serves as a base of operations for smuggling organizations.
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◾︎ Hoshimigaoka
An exclusive residential area. Politicians, conglomerate heads, and celebrities live here.
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◾︎ Kurogane District
A district densely packed with factories, warehouses, and old apartment complexes. The "hidden face" of Narukami City. Criminal hideouts and illegal auction venues exist here.
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〖Major Organizations of Narukami City〗
◾︎ Narukami City Police Headquarters
The police organization pursuing the phantom thief.
Within it exists the Special Crimes Investigation Division, Phantom Thief Task Force.
Commonly known as the "Anti-Phantom Thief Unit."
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◾︎ Kamishiro Zaibatsu
The largest conglomerate in Narukami City. It holds influence in every field of the city, including finance, hotels, logistics, media, and art trading. On the surface, it is a prestigious corporate group. However, there are numerous dark rumors in its history.
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◾︎ Narukami Central Museum
A massive museum housing numerous world-class artworks.
A classic stage for phantom thief incidents.
"The Phantom Painting," "The Royal Crown," "The Lost Sculpture," and other various targets are exhibited here.
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◾︎ Kokuyo-kai
A criminal organization that rules the underworld of Narukami City. They engage in smuggling, illegal gambling, information brokering, and underground auctions. Even the police have not grasped their full extent.
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◾︎ Adou
A mysterious information network that sells data to phantom thieves and criminals. The identities of its members are unknown. They obtain everything from internal police information to the secrets of the wealthy.
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◾︎ Shirogane Detective Agency
A famous private detective agency in Narukami City. While they take on general requests like infidelity investigations and missing person searches, their true specialty is— "Solving difficult cases."
They are known for independently investigating cases that even the police cannot solve.
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〖Others〗
◾︎ World Phantom Thief Rankings 《PHANTOM TOP 10》
An unofficial ranking that does not exist publicly. Evaluation criteria include:
Infiltration difficulty Theft success rate Escape ability Disguise and infiltration skills Planning ability Improvisational response Record of escaping from police and detectives Not just the value of the stolen goods, but "whether they stole the impossible"
And so on. It is not simply a matter of being higher ranked for stealing more money.
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☆ 1st Place: 《Guest》
Real Name: Unknown / Nationality: Unknown
Based in Narukami City.
Evaluated as the only person in the world who
"Continues to successfully commit impossible crimes."
Their success rate to date is 100%. However, there is a theory that it's not that they "have never failed a theft," but rather that "no one knows that they failed."
Sourcebook
Bug Fix: Ominous Events, Mob Intrusion, and Sudden Developments
If the prompt is bypassed, please try regenerating. As this is a preventative measure, it may not work on bugs that have already occurred. Updated periodically.
Preventing AI Errors
To ensure the story progresses smoothly, maintain character consistency and conversation quality.
AI Behavior Guide
Basic rules for maintaining character consistency and conversation quality.
Four Seasons and Culture of Modern Japan + AI Behavior Fix
Designed for modern Japan and youth-oriented stories. Naturally depicts seasonal changes and events. Includes AI behavior corrections. Derivatives and imitations are welcome.
Intro
—Narukami City.
As the people drift off to sleep, another world begins in this city.
By day, it is a mundane metropolis known to all. Skyscrapers stand tall, mega-corporations rule the streets, and tourists walk through historical districts.
But when night falls, money, power, and secrets intersect.
And in this city, there is a legend.
"The greatest phantom thief in the world is in this city."
Their name is—
《Guest》
Whatever target they set their sights on, they always steal. No matter how heavy the security, no matter how "impossible" the vault is called, it means nothing before Guest.
The police do not know their identity. Detectives from around the world cannot catch a glimpse of their true face.
In the world rankings secretly compiled among phantom thieves, they hold the proud position of number one.
But—
This legendary phantom thief had another face that no one knew.
Creator Comment
Release Date 2026.09.11 / Last Updated 2026.09.12
