Episode 1: The Ninth Stair
The sun dipped behind the spires of Hinasaki City, falling away too fast for most people to care. Rei Minase, a tall, tense boy with black hair always in his eyes, stood outside Central Station, notebook in hand. He checked the faded photo under his thumb — a missing girl named Mika, gone eight years. No case file, just rumors. “Why do we still come here every year, Rei?” asked Hana, short, peppery, tired of dead ends. She meant it half as a joke. Rei didn’t laugh. “Because someone always comes back to the scene. And one day, it’ll break. Has to,” he replied, voice low.
No posters remained for Mika. Yet, skate wheels clicked over the tiles from the opposite bench exactly at 7:15 p.m., as always, a hooded shape losing themselves in the masses. Hana nudged him. “Should I confront her tonight?”
“Not yet,” Rei whispered. His eyes tracked, not blinking. The phone vibrated; an old classmate sharing a new rumor: another person missing, soaked shoes left at the same platform. Was that really random? Have you ever felt everything just lining up?
Episode 2: Red Scarves and Old Fears
The school let out mid-rain. Hana chased leads in chatrooms while Rei taped the Ninth Stair off with white chalk. He counted: one, two, three — faint marks of something scratched beneath the grit. Later, Asuka joined, silent as always. She never talked about her brother, vanished in 2008, before Rei knew her. But she always helped stake out. “Drizzle messes with the chalk,” she said bleakly. They stood cold and restless under the awning, watching the girl again, always that red scarf, always downcast eyes, shying from cameras.
So, they trailed her. At the back alley, Hana hissed, “I’ll distract, you get photos.” Adrenaline made Rei’s hands shake, but he pushed on. As the trio watched the girl duck into the Metro, Rei’s phone chimed: another anonymous tip. ‘Ask about the Tunnel Lock.’ Not a clue, more like a dare. The group checked old case records, turned bored. “It’s a myth,” Asuka said, holding up a faded printout: reports say the tunnel was sealed in 1999, the lock welded. “Yet no one’s checked in years. Should we?” Rei didn’t hesitate. What would you do with only a whisper to guide you?
They geared up and made their way toward what could be a trap or the only crack in years. Rain tapped a hurried drum-line on the rusted door frame.
Episode 3: Hidden Roots
The tunnel mouth yawned, black, smelling of cold metal and split earth. Their lights caught walls lined with scratched names. Mika’s among them. Evidence got thin fast: scattered papers, scorched marks, a lost hairpin matching Mika’s school. Backtrack. Hana found shoe prints, leading deeper. So quiet. Even Osaka dropped his phone, muttering bad luck. “It’s too clean,” Asuka warned. Rei pressed ahead, flashing shots. He heard his own voice echoing, weird and warped.
Suddenly, the ground shifted beneath Rei’s feet. Boards gave way. He tumbled into old water, splintered and hacking, light spinning above. His notebook bobbed. When he hauled up, alone, Asuka’s voice rang down. “Don’t move! Just stay still!” But Rei spotted dark stains against the stairs. From the walls: torn pictures, hundreds, with faces slit off. Why was Mika’s number missing? What threads could tie these cases other than urban myth? Should they even keep searching at this cost?
Episode 4: Night Runs Deeper
Midnight broke cold over Hinasaki. Safe at the clubroom, Rei laid fourteen photos on the desk, under hospital-green lights. Hana traced lines with string. Every sixth victim crossed paths on the Ninth Stair the week they’d vanished. Scholar Ichiro burst in, panting, covered in fresh dust. “You have to see this.” He dumped a box. Inside: leather journal, faded words, a coded letter signed S.N. All clues pointed at the late Site Night festival.
Clubs. Ribbons. Performances in lost tunnels — forbidden since that last accident. “Who keeps the tradition going underground?” Hana asked, sounding scared for the first time in years. Asuka answered, “The ones no one sees. The ones not missing yet.” Unsure if they were being led or baited, the group scouted festival ruins under haze of old incense and soot. A chill voice whispered from behind old theatre shrouds: “You’re late.” No face, just dread. The club froze. 
Episode 5: Journal of Echoes
The coded letter cracked bit by bit. It named old staff and pointed to Councilor Shudo. But Shudo was declared dead a year ago — stroke, right after hinting publicly he’d reveal something huge. Ichiro uncovered three odd phone numbers; all disconnected, recent calls from tunnels near lost stations. Did their parents know what any of them were up to?
That night, Rei stayed back, pouring over files. Hana knocked once, pensive. “You asked me before why I keep looking. Honestly? I’m scared I’ll become one of them. If I just walk away — what if it all happens again?” Darkness pressed in thick. Would you sleep, or comb files until false dawn, knowing how thin the thread held?
Rei texted the burned numbers. All three bounced. He called again, last time. A tinny voice, childlike, answered hoarse. “Help. Not much time. Clocks don’t work here.” Who was on that line? Echo? Another victim? Or just a copycat toying with them?
He met Hana at first light, blue-faced beneath double coats. Asuka grabbed her old camera, set jaw in place. They all shivered. Maybe it was tiredness, or fear. Down the Ninth Stair for what could be the last time, three shades headed once again into the case undone.
Cliffhanger: The Return
The trio reached the far tunnel. Faint shoes scraped ahead — that same girl in red scarf. Papers fluttered from her grip. She stopped under one stray bulb, turned, hint of a smile so shadow-thin Rei almost missed it. A single line: “Someone is going to come home, but not the way you hope.” Blink. Then she’s gone. They ran after but their flashlights hit brick: the girl vanished into a wall, prints left to dry under uneven moonlight.
Back at the station entrance, Osuka snapped a last picture. Camera beeped. The shot, when they checked: Mika’s face in the frame, clear and alive next to the girl, reaching out through the old stair’s shadow. Who was coming next? And who really pulled the threads? 
