Prologue
Kazuyuki paces the floor of his one-room flat. The world’s edges always looked a bit blurry to him, since the night of his youngest sister’s funeral. Have you ever had that feeling—like there’s a veil and you’re the only one who notices?
He stares at a worn photo of Sayu. White dress, cheeky grin, twigs in her hair. His mother barely looks at him now. They all think he couldn’t let go. Yet every night at 1:30am, another presence tugs at his chest, heavy but cold.
Between Worlds
Next day, Kay (that’s his nickname, for friends anyway) steps onto the city footbridge after cram school, too tired to dodge puddles. The rush of traffic below goes silent. Above, the air ripples. Suddenly, colors fade—the bridge empties and spirits in loose robes flow past him.
Kay rubs at his eyes. A masked figure confronts him. “The thin child walks both shores,” she whispers. He wants to run, but his own feet betray him. The city peels away.
Domain of Roots
Kay wakes ankle-deep in still water. Four will-o-wisps watch him. There’s a wash of bamboo, spirits moving just out of sight. His breath hangs misty above black mud.
The woman reappears. She tells him her name is Yoru. She says, “People who see us are rare. You cross over in dreams, but dream-walking leaves doors open.”
The Veil Explained
Her words shake his core. Kay chokes, “Did you bring me here?”
Yoru traces runes with her blade. “Almost an accident. Ours is the realm your sister crossed too soon. You must close what was opened, Kazuyuki.” Can he trust her? Would you, faced with that ultimatum from a masked stranger?
Supporting Spirits
Toriko, a clever small animal spirit with hooves and worried golden eyes, bumps his leg for comfort. She tells him, “Not all who wander come by choice. You want answers—but answers here take what you’re not ready to give.” 
Inside the Mirror City
By day, Tokyo carries on. At night, Kay’s drawn into the roots and riverbanks of the spirit world, caught in odd gaps between street and alley. He trails the footsteps he dreams—and smells garden air on city wind. Ami, an after-school friend with streaked blue hair and blunt words, starts to see his moods.
And at school, his hands start jittering. Shadows slink from chalkboards. One teacher—the old artist, Sensei Mihara—offers old ink coins. “Sometimes it helps. My mother had your look too, after all.”
Kay cradles the coin. Strings of faint kanji dance against his skin. Ignore, accept, use?
The Bargain Deepens
Next crossing, the reeds shimmer silver by a black canal. Forgotten spirits hungrily follow Kay’s footprints. He sees a girl in blue—a flicker so like Sayu.
Yoru warns: “Souls left wanting anchor themselves. Don’t speak her name! She’s prey for older things.”
Toriko grabs Kay’s sleeve. “If you listen, she will sing you empty.” Have you ever had to let a voice go, even when your heart whispered ‘wait’?
He almost cries, swallowing a song shaped like his sister’s laughter.
Conflict Surges
Nights pull Kay deeper. On one, frost slicks his shoes as he slips along riverbank stone. The shadows crowd hungrily, muttering his name under thin reeds. Some trade memories for light. Some have none left.
The masked girl (herself half-light, half undone in spirit ribbons) presses a braceleted hand to his chest. “You must bind or be bound.” She urges, “Many doors open out. Fewer lead home.”
An inky storm boils above. It pulls at him, tries to crawl into his heart. Kazuyuki loses balance—feels himself tilting toward somewhere colder, with dark roots and echoing voices.
Moment of Choice
Yoru draws a bleeding thread from his chest. Toriko weeps silver tears. For a heartbeat, he’s in two places: a bright shore, and a shore where his hands are smoke. An image of Sayu, distant, smiling—it blurs and twists, replaced with an empty-eyed wraith.
Kay gazes forward, grits his teeth, and shouts: “Sayu, I miss you, but I won’t be taken.” His voice cracks the vision.
Support from the Living
In school, Ami tugs his sleeve. “You’re not here,” she pouts. “D’you even remember what I said yesterday?” Kay squeezes out an awkward laugh, croaks, “Sorry. Not sleeping.”
She frowns. “Just tell me you’re not in some scrap.” Kay flinches, can’t meet her gaze.
Ancient Ties Invoked
On the next crossing, Kinji Mihara stands in the roots, younger and ageless. “Time means little here. That ink tied a thousand promises. Yours is raw, new-made.” The old sensei’s lines burst like nerves. Is every trusted adult hiding spirit pasts?
Kinji helps piece together clues: children lost, symbols marred by human pain, a pact unfinished. Yoru guides, but another spirit marks Kazuyuki—a hunched, stalk-eyed figure picks up his scent.
The Hunt Begins
Sudden hunts break out in the mist. Kazuyuki and Toriko scamper through spirit crowds. The new threat, Monkey’s Grin, flickers in and out, leaving bite marks on air. Each night shortens, time leaking forward more slowly in Kay’s dayworld.
Kay dares slower crossings, in daylight—ghost-blotches hide in sun-bright puddles. Ami trails him, sometimes glimpsing odd shapes. Do you think she’d follow twice, without asking?
Ethics of Looking Back
Inside a shrine, Kay faces another child—a lost ward who’s given up his face in trade for an easier path. Yoru says: “Nothing given ever stays the shape you think.” Kay offers a memory: how Sayu once saved a stray dog, just before summer.
The child takes that gift, his own spirit flickering more solid. “Closure,” Yoru murmurs, approving. But Kay’s hands shake, spirit coin growing hot in his pocket. Are some sacrifices one-way?
Preparing to Seal the Rift
As weeks pass, each crossing strengthens his link to the spirit world—and weakens his tie to the living. On a cold evening, his own outline is thin in bathroom glass. “You need an anchor,” says Toriko. Kay scrawls Sayu’s name in ink, draws the kanji for home next to it. 
That night, Monkey’s Grin tries to drag Kay into secret roots hidden beneath city bridges. Yoru battles beside him, using fans etched with shadow scripts. Toriko’s defiance sparks aurora-like rays, scattering lesser spirits. Kay flees, battered, half-remembering sunlight.
A Sister’s Last Wish
Kay’s next dream-stride, he finds a locked door at the river’s source. There’s something behind it—Sayu’s laughter, followed by empty echoes. Yoru presses her blade into Kay’s palm.
He turns, to see Ami, dazed, stepping through the rift behind him. Has the real and unreal come too close now? Will Kay choose to bring closure and lose memories—or keep walking unbound, ghost between worlds? The lock clicks. The key glows, thin and blue, between his hands.
Cliffhanger
Just as Kay places his hand to the ancient door, thunderstorms split the river. Yoru and Toriko both vanish. A single child’s voice, warped by sorrow, beckons him inside.
Does Kay follow and risk all, or shut the crossing forever? 
If you were in his place, would you do the same?
