In a quiet, secluded park, Kariya Matou waited in silence.
Just a few days earlier, he had received a sudden call from an unknown man. The voice on the other end had spoken plainly, even coldly: Sakura was about to be adopted into the Matou family—as an adopted daughter to that man.
At first, Kariya had thought it was some sort of scam, a hoax from someone who'd dug up his personal information. But when he called his childhood friend, Aoi Tohsaka, to confirm it—
—he realized it was all true.
Without a moment's hesitation, he called the number back. While demanding to know what had happened, he rushed to book a flight back to Fuyuki City. His heart was pounding, rage boiling just beneath the surface.
The moment he stepped off the plane, he was ready to charge straight to the Matou estate, confront that grotesque man—his "father"—and tear Sakura from that accursed house.
But the voice on the phone had told him otherwise.
Come to this park, it had said. Wait here. Sakura will come to you.
There was something strange in that voice—an unplaceable sensation that echoed in his bones. Something that felt… wrong, and yet, impossible not to trust. As though some invisible hand guided him here, to this forgotten corner of the city.
Once he arrived, Kariya felt a sudden clarity. Confused, yes—but calm. And since he was already here, he figured he might as well wait. If Sakura didn't show tonight, he would go to the Matou residence himself.
He sat alone on a public bench, his foot tapping the ground in anxious rhythm. His hands rubbed together restlessly, and he blew into them for warmth. Fuyuki hadn't quite entered winter yet, but the chill had begun to creep in—especially in a park like this, beneath a clouded sky. His thin clothing did little to keep the cold at bay.
Suddenly, from the street bordering the park, came a sharp, grating sound.
It took Kariya a moment to place it—the screech of tires skidding violently across pavement.
Then he saw it: a bicycle racing toward him at breakneck speed.
He stumbled back in alarm.
The woman's bicycle performed a swift, elegant drift just before reaching him, coming to a perfect stop with a practiced motion.
Kariya's eyes widened.
The rider was a striking woman with long, flowing purple hair and glasses, dressed in a sleek black turtleneck sweater. And behind her, seated on the rear of the bike, was a small black-haired girl—
—her eyes spinning like mosquito coils.
Sakura Matou trembled on the backseat of the bicycle, her small frame shivering in silence.
"Sakura!"
Kariya Matou rushed forward, hastily lifting her down and settling her gently onto a nearby park bench.
Dazed and disoriented, Sakura collapsed against Kariya's knee, her breathing shallow. As he steadied her, the woman with long, straight violet hair quietly parked the bicycle and approached him. Her eyes locked onto his face with calm precision.
"Excuse me... Are you the guardian of my Master?"
"You are…"
Kariya looked carefully at the woman standing before him. She carried a strange, unplaceable air—one not easily described. Though her beauty was stunning, the sort that could turn heads anywhere, Kariya, who still pined for another man's wife, remained unmoved by her looks.
He furrowed his brow, digging through recent memories of the current timeline—of major events likely to unfold in Fuyuki.
"You're… a Servant?"
"Yes," she replied without hesitation. "Servant—Rider."
"Then… your Master is…"
Kariya's eyes shifted slowly to the black-haired girl nestled in his arms.
"Yes. This little one—I believe her name is Sakura—she is my Master," Rider answered with perfect calm.
Kariya's gaze turned grave as he looked down at Sakura. He knew all too well that summoning a Servant was no simple feat—it was an act riddled with danger and unpredictability. Some Masters died in the attempt. They might summon malevolent spirits or rebellious Heroic Spirits that turned on them instantly. And in cases like Sakura's, where the Master was just a child with a fragile supply of mana, even surviving the summoning could be fatal.
Suddenly, a familiar voice rang out in both Kariya and Rider's minds, clear as thought yet resonating in perfect sync:
[Ahem. May I offer a word of advice?]
Startled, Kariya and Rider exchanged looks. The voice had echoed simultaneously in both of their minds—whoever it was had mentally linked all three of them into a shared channel.
[Whatever your reason, sir, I want to thank you. Thank you for helping Sakura escape that hellhole.]
[My thanks as well. Your mana allowed me to unleash my Noble Phantasm—and that was what gave us the power to break free from that basement.]
[No need to thank me. Like I said, that power was granted to you by the Great Loli-Con Association... Besides, the little girl did help me once. But! Don't you dare tell her about that, understood?]
Both Kariya and Rider nodded inwardly, agreeing to the mysterious voice's request.
[Excellent. Now then, Mr. Matou, I have a proposal.]
[Please, go ahead.]
[As you've surely realized, Sakura's mana is nowhere near enough to sustain a Servant. She's too young to bear the burden of this brutal war. So, allow me to help: I can transfer Rider's contract from Sakura... to you. You'll become her new Master—and take her place in the Holy Grail War. What do you say?]
"I accept!" Kariya responded without hesitation, his voice firm.
[And you, Rider? Are you willing?]
Rider turned to glance at Sakura, who lay unconscious on the bench. After a brief silence, she nodded.
[I accept.]
[Perfect. Then the contract is sealed.]
Before their eyes, the Command Seals on Sakura's hand began to fade—and in their place, a new set of glowing symbols slowly etched themselves into Kariya's own hand. A fresh magical bond took root between Kariya and Rider—one that pulsed faintly with mana and fate.
[One more thing. Get some mercury—or if you can't afford it, a bit of blood will do. Draw a summoning circle according to this diagram and call forth another Servant. This Holy Grail War... is going to be a little crowded. But whatever you do, don't use human blood. One particular saintly lady gets very upset about that.]
As the voice trailed off, a single sheet of paper floated gently from the sky, landing in front of Kariya. He picked it up, revealing an intricately drawn summoning circle and a spell written beneath it.
[Use this to summon a Servant. And this—this is your mana supply. With your pathetic level of magecraft, there's no way you can sustain even a B-rank Heroic Spirit. So… here, take a little cheat code.]
A glowing blue crystal suddenly appeared in Kariya's coat pocket. At the same time, he felt a surge of power flood into his right arm—a sensation like magic rewiring his very nerves.
[From now on, your right arm will cancel out all magical energy—except for True Magic and Noble Phantasms. Use it wisely.]
Kariya's expression turned serious.
"Why… why are you helping us?" he asked the voice aloud.
[Good question. First: I don't want you dying, especially after I went through all this trouble to find Sakura a proper guardian. Second: when the time comes during the Holy Grail War... I want you to follow my orders. Sound fair?]
Kariya thought for a moment. Then, quietly, he nodded.
Lifting Sakura gently into his arms, he looked out into the dark of night—still, endless, and unfamiliar.
A little lost, he turned to Rider.
"So... where do we go now?"
Rider said nothing. But once again, the voice returned—cheerfully, almost smug:
[Head left a hundred meters. Turn left again. There's a hotel—get a room.]