Yumihara's western valley had always been silent.
A land untouched by war, unclaimed by any tribe, avoided even by the birds that circled the sky but never dared descend. The locals called it Kurai-Utsuro — the Hollow of Darkness — a barren stretch of cracked soil and dead stone.
Tonight, it breathed.
The first tremor struck the excavation site like a pulse rippling beneath Ren Arashida's boots. He felt it before he heard it — a deep, resonant vibration that spread through the ground in a perfect rhythm.
Not an earthquake, Ren realized. Something… intentional.
Sand spilled down the sides of the excavation pit. Tools clattered. Lamps swayed wildly on their hooks.
Workers froze.
Some dropped to their knees.
Others muttered prayers to the mountain spirits.
Ren stared as dust rose like ash from the earth, and a sound — low, humming, almost alive — echoed beneath the valley.
The tremor lasted seven seconds.
But it was enough to change everything.
Ren wiped dust from his face and shouted, "Status report! Is everyone alright?"
Kaede Mori, his sharp-witted assistant, stumbled toward him, eyes wide. "Ren-san… something opened. You need to see this."
Her voice trembled — not from fear, but from awe.
Ren followed her down the uneven ramp of the excavation pit. Wind howled overhead, scraping along the valley walls like claws. Lanterns flickered. The air felt heavy — thick with ancient breath.
Kaede pointed to the deepest part of the pit.
Ren stopped cold.
Where there had been nothing but solid earth moments ago… there was now a cavernous opening. A perfect circle carved into the ground, dust falling from its edges like the aftermath of something awakening.
"No survey ever detected this," Kaede whispered.
"That's impossible," Ren said.
But the chamber disagreed.
A faint glow pulsed from within its darkness — rhythmic, steady, almost like a heartbeat.
Ren descended slowly, Kaede and two workers trailing behind him. The deeper he went, the hotter the air felt. Not the heat of the sun… but something internal… living.
At last he stepped through the broken arch of the chamber.
And his breath stopped.
It was massive.
Circular.
Walls covered in carved sigils that moved when he tried to focus. Not illusions — motion. Lines that twisted like serpents, shapes that breathed, symbols he didn't recognize from any Yumiharan era.
Kaede whispered, "What language is that?"
Ren swallowed. "None I've studied… and I've studied all of them."
The air hummed louder.
And then he saw it.
Floating above a lone pedestal at the chamber's center.
A Seishin Stone.
Not small, not cracked, not mild like the ones in museums or shrines.
No.
This one was colossal — black as burned obsidian, etched with glowing red veins that flared like trapped lightning.
It floated a few inches above the pedestal, slowly rotating.
Alive.
Kaede gasped, "Ren… it's levitating."
Ren stepped forward despite every instinct screaming at him not to. His chest tightened the closer he came to the stone. His breath hitched.
His blood vibrated.
The stone pulsed.
And the entire chamber pulsed with it.
KA-THROB.
KA-THROB.
KA-THROB.
Ren staggered, grabbing his head as a shockwave tore through him. A strange warmth surged through his veins, threading into his bones, into his mind.
Then the visions came.
A battlefield drowned in fire.
A sky torn open by screaming spirits.
A black temple collapsing into a void.
A warrior with red eyes — carrying the same Seishin Stone — roaring as shadows wrapped around him like armor.
Ren fell to one knee, gasping.
Kaede rushed forward. "Ren! Ren-san, what's happening?!"
He couldn't answer.
The stone pulsed again.
And a voice — old as time and cold as death — whispered inside his skull:
You have finally arrived, Heir of the Ninth Seal…
Ren froze.
Not because of the voice.
But because he wasn't alone.
From the far corner of the chamber…
A figure formed.
A shadow.
Tall.
Twisted.
Dripping darkness like smoke.
Its eyes burned faint crimson.
Not glowing.
Burning.
Kaede didn't see it. She was still checking Ren's pulse, frantic.
But Ren saw it clearly.
The creature tilted its head — studying him like prey.
Ren backed away, breath broken, heart pounding.
The shadow lifted a hand.
Its fingers stretched impossibly long as it reached toward him—
And suddenly, the Seishin Stone ignited.
A violent burst of red light erupted from its core, blasting the shadow backward. The creature hissed — a sound like metal dragged across bone — and vanished.
Not fled.
Not retreated.
Vanished.
Ren collapsed, drenched in sweat, vision blurry.
Kaede shook him. "Ren! Talk to me! What happened?!"
He gasped, "I saw… something."
"What?"
"A shadow."
Kaede frowned. "There was no one else here."
Ren pressed a shaking hand against his chest… and froze.
A mark glowed through his shirt.
A sigil burned into his skin.
The same one carved on the chamber walls.
The same one on the Seishin Stone.
Kaede saw his expression and grabbed his arm. "Ren—what did you do?"
"I didn't touch it…" he whispered. "It touched me."
---
Outside, the sky rumbled though there were no clouds.
Wind howled down the valley, scattering sand into spirals.
The workers muttered, backing away from Ren as if he carried a curse.
Maybe he did.
Kaede helped him out of the pit. "We need to contact the University. Daigo. Hiroto. Anyone."
But Ren wasn't listening.
He felt it.
Inside him.
A pulse that didn't come from his heart.
KA-THROB.
KA-THROB.
KA-THROB.
The Seishin Stone had awakened.
And it had awakened him with it.
He reached the top of the ridge, breathing hard. The sunset cast long shadows across the valley —
And one shadow didn't belong.
A tall figure stood on the ridge opposite them.
Still.
Watching.
Red eyes glowing faintly.
Ren's blood froze.
The figure slowly tilted its head… exactly as it had in the chamber.
A twisted smile stretched across its darkness.
Kaede turned. "Ren-san? What are you looking at?"
Ren blinked—
The figure vanished.
Not walked away.
Not dissolved into wind.
Vanished.
He whispered, "It's watching me…"
Kaede touched his shoulder. "Let's get you cleaned up."
But Ren barely heard her.
Because he knew something now.
This wasn't a discovery.
This was an awakening.
And whatever slept beneath Yumihara…
Wasn't sleeping anymore.