The third-floor hallway was always quiet. Too quiet.
Kai walked it alone, long after most students had gone home. Only the humming of old fluorescent lights kept him company. The janitor's cart sat abandoned by the stairwell — as if someone had left in a hurry.
Then he heard it.
A soft tapping.
Three times.
Coming from the wall between the old art room and Room 3-C.
There was no door. Just a stretch of faded wallpaper and a rusted fire extinguisher mount.
But something about the rhythm — deliberate, almost human — pulled him closer.
He ran his hand along the wall.
Knuckles brushed against a shallow groove. Faint. Almost invisible unless you knew where to look.
Kai took a deep breath and pushed.
The panel creaked open.
Dust billowed out like breath from a long-dead mouth. Inside was a narrow stairwell descending into darkness, lit only by a dying emergency light.
He hesitated.
Then stepped inside, closing the panel behind him.
At the bottom of the stairs was a door with peeling paint.
On it:
"Storage – B1"
But the school had no basement on the official blueprints.
Inside was a wide, low-ceilinged room. Dust and mold coated everything. Broken desks. Stained textbooks. Rotten uniforms folded neatly in stacks.
And something worse.
Student ID cards. Dozens of them.
Scattered across the floor like discarded candy wrappers. Many were cracked, their photos faded — but one caught his eye.
Tanaka Mayu.
Pinned to the far wall, warped with moisture, was an old black-and-white photo.
It showed a classroom. Thirty students. Smiling. Uniformed.
Kai stared at it for a long time.
The photo was dated: April 1989.
Near the center stood a girl who looked exactly like Mayu.
Younger. But unmistakable.
His heart pounded. She hadn't just disappeared — she'd already existed once before.
In an overturned drawer, Kai found a journal — leather-bound, cracked at the spine.
Inside, shaky handwriting detailed a student's descent into paranoia:
"They mimic. They replace. They erase.
It always begins with a whisper. Then a face. Then a mirror.
The school doesn't hide the truth. The school feeds it."
"We tried to trap it in Room 3-C. But the room is a mouth. We only fed it more."
"I'm forgetting my own name now. It's using it."
The final page simply read:
"I think I'm already gone."
Kai turned to leave.
But the stairwell door had closed.
Worse — when he reached it, it wasn't there anymore.
Only solid wall.
The emergency light flickered once, then died.
Darkness swallowed everything.
And somewhere, behind him, something began to breathe.