Somewhere past 3 a.m., in a forgotten wing of the National Library's sealed archive, a twenty-something thief named Rei crouched beneath a security laser and muttered to himself.
"Easy in, easy out," he said. "Just a book and a shiny trinket. No cursed monkeys or ancient mummies. No problem."
Rei was not a professional thief. He was a YouTube Urban Explorer with lockpicks and an ego. His follower count had stalled, and his cash was low. So when a sketchy occult forum whispered about a sealed room in the Tokyo Library that once held relics of a banned magical order, he charged in with a GoPro, a crowbar, and the optimism of someone who hadn't read enough horror manga.
He didn't expect the archive to be real. He didn't expect the door to open. And he sure as hell didn't expect the book to glow when he touched it.
The book was bound in blackened vellum and stitched shut with what looked like gold thread. Sitting beside it was a bronze medallion in the shape of an inverted star—too heavy to be fake, too cold to be normal.
Rei lifted both and stuffed them into his backpack.
"Score," he whispered, grinning as his camera blinked red. "This'll get me trending for sure."
Back in his cheap one-room apartment in Nerima, Rei threw the bag onto the kotatsu table and popped open a beer. He unwrapped the book and medallion like a kid on Christmas.
"Maybe it's a cult diary. Please let it be a cult diary," he muttered, flipping on the camera again. "Occult Book Unboxing—Episode 1."
He cracked the seal with a kitchen knife.
The book opened on its own.
At first, the symbols meant nothing—swirls of runes and ink-blot diagrams. But the longer he stared, the more they pulsed. Like they wanted to be read.
And then… he did read them.
"Let that which binds the soul to myth be undone—"
His breath caught.
"—by this seal and this vessel, I summon thee across the veil."
The medallion on the table began to smoke. A deep hum filled the room.
"Wait," Rei said. "What?"
The lights blew out.
The room exploded in light and wind. His camera cracked. Glass shattered. A sigil—seven-pointed and glowing pale green—burned itself into the ceiling.
From the center of the chaos, a voice echoed.
Not booming. Not divine.
Just... bored.
"Really? You?"
The wind died. The light faded.
And standing in his wrecked living room, brushing soot off her jeans, was a girl.
She looked eighteen, tops. Hair short, silver. Eyes sharp like a street cat. She wore a black bomber jacket with a white symbol on the back, and combat boots.
"Oh, great," she said, looking around. "Another accidental summoning. How original."
Rei blinked. "Wait. What—who—?"
"You tried the book, didn't you?" she sighed. "Well, congrats. You summoned a Servant. Me. Now you're in a war you don't understand."
She flicked her fingers. The bronze medallion snapped into her palm and dissolved into mist.
"Name's Rook, by the way. Class? Assassin-slash-Rider. But let's not get formal."
Rei stood frozen. "This is a prank, right?"
Rook rolled her eyes. "Kid. You lit the ritual. You burned a binding seal. You called me. Whether you wanted to or not, you're in the Color War now."
"Color—what?"
"The Holy Grail War. But with upgrades. The usual grail war had a servant of one class, but this... two." She pointed to the faded sigil above his head. "You're registered now. Marked. You're officially part of the bloodbath."
She picked up the broken GoPro and examined it.
"You wished for something, didn't you?" she said casually. "That's how it works. You summoned me with intent. Even if it was stupid."
"I just—" Rei paused. "I didn't wish for anything."
"Then why steal the book? The artifact? Why touch them?"
"…I wanted something big," he said finally. "Something to change my life."
Rook gave him a long, amused stare. Then she laughed.
"That counts."
Two Days Later, Rei's apartment was already a disaster zone. Now it was also a war room.
Rook had taken control like a small, smug general. Maps of Tokyo littered the walls. Threads of red string connected ley lines and Servant-sighting rumors. Rei couldn't tell if she was mocking him or prepping for battle.
"So what do I do?" he asked over his third cup of instant ramen.
"You stay alive," Rook said flatly. "While I kill the others."
"Kill? Like, kill-kill?"
"This is the Holy Grail War, Rei. One Grail. Seven Servants. One winner. You want your wish? You survive."
She sat cross-legged on the table, staring at her hand. "We're White. That means I'm the Assassin-Class Primary. Speed, intel, infiltration. But I've got Rider as a backup, so transport's covered."
She whistled, and her mount materialized—a spectral motorcycle made of bone and chrome, humming like a caged ghost.
Rei fell off his chair.
"Let me guess," he muttered from the floor. "Other people summoned gods and heroes. You're what, some ghost biker?"
Rook snorted. "Wanna guess again?"
"…Who are you?"
She turned her eyes on him. For a moment, they gleamed with something ancient and terrifying.
"Melinoë.""Daughter of the dead. Walker of dreams. The silence between heartbeat and scream."
Rei swallowed hard.
"…Cool," he whispered.
That night, Rook walked the rooftops of Shinjuku, her figure flickering like mist beneath moonlight. Rei watched her from the fire escape and realized two things:
He was in way over his head.
He didn't care.
Across the City. In an abandoned shrine on the edge of Setagaya, another summoning circle burned into stone.
Flames curled upward. White light seared through space.
A woman stepped forward from the glow.
She was tall. Armored from head to toe in steel chased with gold. Her helm shone like sunrise. A crimson plume curled from its crown.
Her eyes, unseen beneath the visor, locked on the boy standing before her.
He was young. Calm. Not surprised.
She bowed slightly, placing her lance into the ground like a knight pledging loyalty.
"Are you my Master?" she asked, her voice soft but echoing like temple bells.