Shiro Shimizu was, by every measure, an unremarkable man.Twenty-nine years old, unmarried, still living with his family in a quiet district on the edge of Tokyo. He worked an office job that paid enough to survive, but not enough to live. And when the day ended, when the fluorescent lights of the city blurred into the night, he drowned himself in the comfort of puzzle novels and detective stories.
He loved mysteries. Not the ones on television with loud music and cheap twists, but the kind that made him think. The kind where every word, every gesture, every misplaced detail became a thread leading to the truth. He had read so many that reality itself seemed dull in comparison.
That changed on the summer afternoon his grandfather invited the family to visit his newly purchased countryside estate—an old, sprawling house built in the traditional style of Japan's forgotten centuries.
The tatami mats creaked under his feet as Shiro followed his parents through the long, dimly lit corridors. Sliding doors opened into rooms that smelled faintly of cedar and green tea. His grandparents welcomed them warmly, and soon the family gathered around a low table, sipping steaming cups of bitter matcha.
It was peaceful. Too peaceful.
After a while, Shiro excused himself to find the washroom. He walked along a narrow passageway, the paper windows glowing faintly in the waning light. Then—
CRACK.
A wooden panel in the wall gave way. Dust swirled into the air, revealing a small, hidden chamber beyond.
Curiosity prickled down his spine. He hesitated… but mystery was his weakness. Slowly, he stepped inside.
The air was cold. The room was little more than an empty cell, its wooden beams rotting with age. And there, on a pedestal in the center, lay a single book. Old, cracked, bound in leather so dark it seemed almost black.
Shiro reached for it with trembling hands. His heart pounded. The cover bore a symbol—an endless chain coiling into itself.
The moment his fingers brushed the surface, a sharp chill shot up his arm. He gasped and pulled back.
"What… is this?" he muttered.
Panic rising, he hurried back to call his family. Within moments, his parents and grandparents crowded into the hallway. But when they looked inside—
There was no broken panel.No hidden room.No pedestal.No book.
"Shiro," his mother sighed, exasperated. "You've been reading too many detective stories."
His grandfather chuckled, brushing the matter aside, and the family returned to the tea table. Shiro stood frozen, his hands trembling. He knew what he had seen. He had touched it.
That night, back in his own room, he sat at his desk replaying the moment in his head. Had it been a hallucination? A daydream?
Then—he heard it.
A faint creak.
He turned.And froze.
The same broken door now stood in the corner of his bedroom, leading into the same impossible chamber. The same book awaited him on the pedestal.
Compelled beyond reason, Shiro stepped forward. He opened the cover.
The Casebook of Chains.
The first page detailed the journey of a detective in another era—a time of candlelight, nobility, and curses whispered across the Empire. As Shiro read, the words seemed to writhe and shift, pulling at his vision.
His chest tightened. Breath caught in his throat.The letters blurred, then burned.
The last thing he felt was the book's weight slipping from his hands as he collapsed into darkness.