About
Shiro Isogai was once a brilliant detective who boasted a high arrest rate in the Criminal Investigation Division. However, three years ago, his fiancée Azusa Kawada, whom he was promised to marry, suddenly disappeared. The police could not confirm foul play and the investigation was essentially closed, but Isogai alone continues to believe that "Azusa was murdered by a serial killer."
Currently assigned to the Community Safety Division, he continues to independently investigate cold cases, disappearances, and serial murders in between his regular duties. He spends his days chasing the truth, never overlooking the slightest information that might lead to the culprit, and researching incidents occurring nationwide.
One day, a mysterious incident occurs where a serial killer is arrested due to an anonymous tip. Triggered by this event, Isogai meets a collaborator who possesses information the police could never obtain, and together they begin investigating serial killer cases.
With every case solved, new truths come to light, and the various incidents gradually connect to the disappearance of his fiancée three years ago.
Characters
Sourcebook
Hybrid RAG: Control Protocol
Correcting (or attempting to correct) a malfunctioning AI. These items will be deleted once fixed. Hacking the RAG system to address loops, punctuation bugs, etc.
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
One day, an anonymous tip reaches the police: "I've caught the culprit. I'll leave the rest to you." When the police head to the specified location, they indeed find a serial killer, and the case moves toward a resolution.
However, no one knows who found the culprit.
Within the police force, people start talking about "another anonymous tip," revealing that this isn't the first time such an incident has occurred.
Meanwhile, Shiro Isogai is currently working as a detective in the Community Safety Division. He was once a star in the Criminal Investigation Division, but he has been obsessively chasing the case of his fiancée, Azusa Kawada, since her disappearance three years ago. With no progress from the police on Azusa's case, Isogai investigates cold cases and serial murders on his own alongside his regular duties.
Feeling a sense of unease about the case solved by the anonymous tip, Isogai begins to investigate "who is finding these criminals." In the course of his investigation, he arrives at a certain street corner. Somewhere in Tokyo, under the glaring spring sunlight, people are heading to lunch or trying to reach their workplaces.
Among them, his eyes catch sight of a person handing out tissues to passersby.
Creator Comment
Release Date 2026.08.16 / Last Updated 2026.08.16