"That'll be 14,700 yen," the taxi driver announced, glancing at Ryuuto through the rearview mirror.
"Sure, just a sec."
Japanese taxi fares had to be the only ones in the world more expensive than hiring an escort. Mentally grumbling about the ridiculous prices, Ryuuto pulled two large bills from his wallet.
"Thank you very much. Please take care," the driver said.
Ryuuto climbed out of the cab and walked through the orange glow of sunset toward a gloomy, imposing mansion. This was the Matou residence—the number one must-visit destination for anyone who found themselves transported into the Type-Moon universe.
You might skip the Clock Tower or even Chaldea, but no Type-Moon transmigrator would pass up a chance to visit the Matou mansion!
Standing in front of the Matou mansion amid the chirping of evening insects was a man who looked like a walking mummy. His sharp eyes peered out from sunken sockets, and despite his small frame, he radiated an unsettling pressure.
"It's been a while, Ryuuto."
"Hey there, Zouken," Ryuuto greeted him with a casual wave. "Good to see you're still alive and well."
The old man was Matou Zouken, master of this mansion and head of the Matou family—one of Fuyuki's three founding families.
He wasn't just any old man, though. Zouken was actually one of the creators of the Holy Grail War and the creator of the Command Spell system. Back in the day, when he went by Makiri Zolgen, he had been a talented magus. But now he was just a creepy old monster who had managed to survive for five hundred years by feeding on human blood. The guy couldn't even step into sunlight anymore—a literal non-human creature straight out of a horror story.
After a quick chat with Zouken at the entrance, Ryuuto made his way through the gloomy hallway of the Matou mansion and settled onto the sofa in the guest room.
"I've obtained the qualification." Ryuuto said, holding up his right hand to show Zouken the three crimson marks that had appeared on his skin when he'd entered Fuyuki a couple hours earlier.
"Hmm, that's... an interesting pattern," Zouken observed. "This Holy Grail War might be worth watching. But you didn't come here just to show me that, did you?"
"Sharp as always, old man. You're right. I actually came to say my final goodbye to Sakura."
Zouken's cloudy eyes studied the young man carefully. "Meaning what, exactly?"
"Meaning it's time to fulfill our agreement," he replied casually. "I need you to implant the crest worms into Sakura's body tonight."
At those words, Zouken's mouth curved into a disturbing smile. "I wasn't wrong about you after all. You truly are a wonderful man."
"Haha... right back at you."
In the dimly lit room, the handsome young man and the decrepit old magus exchanged glances, both breaking into sinister smiles.
Sunlight filtered through the curtains, casting an orange glow across Zouken's face as his mind drifted back to the day he first met Ryuuto.
…
A year ago, just days after the Matou family had taken in the second daughter of the Tohsaka family. The moment Zouken first laid eyes on Ryuuto, the 500-year-old monster felt as if time itself had frozen.
The young man had a small, slender build, yet somehow radiated a presence far greater than his size suggested. His face was unnaturally beautiful, as if not belonging to a human. He also wore a smile that never reached his eyes.
What Zouken found most oppressive were the young man's pitch-black, ice-cold pupils.
Just looking into them made the old magus feel like he was being pulled into an absolute zero black hole.
What kind of monster is standing before him? That was his first thought.
"I am a demon."
The old man accepted the young man's introduction without question.
Matou Zouken was essentially a worm, slowly rotting while feeding on human lives. Ryuuto was a dragon, capable of evolving by consuming souls. They existed on completely different scales and were opposite in nature, yet shared one crucial similarity—both were evil creatures hiding behind human faces.
…
A year ago, Ryuuto approached Zouken with an unusual proposal.
"I'll fight in the Fourth Holy Grail War for the Matou family," he'd said. "In return, you'll hold off on implanting those worms in Sakura's body for one year. During that time, you won't touch her, and I'll visit her at the Matou house occasionally. Don't worry—I have no personal interest in the girl. She's still Matou property. When the year is up, the Tohsaka daughter is all yours."
"And why exactly would you want this?" Zouken had asked, unable to figure out Ryuuto's true motive.
"I just want to build a good relationship with the girl," Ryuuto replied with a cold smile. "...before she gets acquainted with your worms."
"...!!!"
When Zouken finally understood what Ryuuto really meant, the old magus's eyes had widened in shock. The young man standing before him was a monster beyond even Zouken's imagination.
Ryuuto's scheme was simple but cruel: first, gain the girl's complete trust, then utterly betray and hurt her. He wanted to raise this innocent child up to the clouds, only to slam her hard against the ground. Anyone could imagine Sakura's future desperation, hatred, pain, and heartbreak.
As Zouken stared at the beautiful young man with those pitch-black eyes, he felt something he rarely experienced—genuine fear. This person was truly a monster who fed on human suffering and actually enjoyed it.
They sealed the deal, and with that, the magus and the demon formed their contract. Zouken would guarantee Sakura's safety and well-being for exactly one year, until the day Ryuuto decided it was time to "enjoy" her.
In exchange, Ryuuto would fight for the Matou family in the Fourth Holy Grail War. If he won, he'd hand over the Holy Grail to the Matou without conditions. Obviously, the contract also included clauses preventing them from harming each other, among various other terms.
He was the creator of the Command Spell system itself. When it came to contracts and binding spells, Zouken was pretty much the world's leading expert. No matter how powerful Ryuuto might be, he couldn't break the contract—just like how Heroic Spirits can't resist Command Spells.
Zouken felt quite pleased with this risk-free arrangement and even found himself developing a grudging admiration for Ryuuto.
Over the next year, Ryuuto traveled between Tokyo and Fuyuki every three weeks. Each visit, he'd bring Sakura expensive gifts and souvenirs you could only find in the capital, all just to see the girl smile.
The Matou house was incredibly gloomy and cold—definitely not a place where any child should grow up. So it wasn't surprising that Ryuuto easily broke through the girl's emotional walls and became her main source of comfort.
Sakura began shyly calling Ryuuto "niisan" and gradually opened up to him, sharing her genuine smile.
Strangely enough, after leaving her capable sister's protection, Sakura actually became a bit more outgoing than she had been in the Tohsaka household.
Zouken watched all this unfold with quiet satisfaction.
And then, just like that, the one-year agreement came to an end.
Ryuuto gave Zouken two weeks' notice to prepare what he called the "worm pit."
Two monsters wearing human faces were setting up their elaborate ritual for a pure-hearted girl who was still living in a dream world.
Tonight was the night.