Confusion. Fear. Panic.

Those three are the only thing running through Ritsuka Fujimaru's head, and nothing else.

I mean, how could he not?

The love that others once shared with him, the peace that filled his everyday life—

All of it vanished in just a blink of an eye.

Humanity, the world as he knew it is now gone – incinerated.

And despite all that, it is now his sole responsibility to restore it.

To save the world.

As if someone completely normal like him can do that sort of thing.

He didn't even know that magecraft was an actual thing until just a few hours ago.

And now he's stuck here, lying on the ground, cold sweat running throughout his body.

He curses the fire around him, the hellish landscape that "2004 Fuyuki City" for not helping the situation.

He hears a set of heavy footsteps coming in his direction.

Just the sound of that thing walking causes the hair on the back of his neck to stand up.

He continues to run, breaking for the leyline that he had constructed with his friend – now his Servant – earlier.

The thing had been chasing them for probably half an hour by now, and in the middle of all that he had to take a different path from the shield girl to save themselves.

He really hopes she's safe, but he also knows that he can't do anything by himself—

The leyline is finally in sight.

As a small spark of hope enters his heart, Ritsuka trips and loses his balance, falling face first into the summoning circle.

The mere presence of him causes it to glow and light up with mana, ready to be used.

—The footsteps grow closer with each passing second.

Fear and panic rush up his head, and his instincts take over.

He starts channeling his magical energy – whatever left that he can muster – in a desperate attempt to save himself.

He knows he doesn't have the catalyst for a proper summoning.

He may be a complete beginner mage, but he knows that much, at least.

But there's no other choice, is there?

With a cry, he flares up his magical circuits, letting out whatever small amount of magic left inside him.

He hopes someone will answer his call.

He hopes that someone will get him out of this mess.

But even more than that…

He hopes whoever this person might be will bring back the love and peace that he once knew—

The summoning circle emitted a blinding flash of light, causing Ritsuka to cover his eyes.

As his sight returns, he sees someone standing in front of him—

A black-haired man, wearing a brown trenchcoat. Underneath that is a grey, plain shirt, with a pair of generic-looking jeans to match. His shoes were mismatched, which Ritsuka found odd – a red sneaker and a blue sneaker respectively. A yellow muffler was wrapped around his neck, and on his face was an equally confused look.

In his right hand is… a sword? Whatever it is, it's a weapon – a weird one at that. It's as if someone glued a drill onto a hilt—

Could he be a Saber…?

No, judging from his appearance—

The newly summoned Servant looked at his hand and pondered out loud.

"A Caster this time, huh…"

Well, that answers Ritsuka's question.

—The thumping grows louder, increasing in volume.

Sensing the danger, the Caster stepped forward in front of his Master, intending to protect him from whatever is after his life.

He pulls out a strange device – a black, rectangular thing with a large, red crank coming out from the side.

"I don't really get what's going on," he says, slamming the device on his waist, "But let's start the experiment, Master."


Probably will keep this a one-shot but let me know if you want more lol.

Just something I wrote on a whim after the idea came to me.

Well, as always, reviews of all kinds are appreciated, so please leave one and have a nice day!

(I might write a similar thing for OOO next.)


The absolutely brilliant, genius physicist Kiryu Sento, more commonly known as the great hero Kamen Rider Build, has appeared once more! This time manifesting as a first-rate Caster Servant, he has decided to help his pitiful master save the world purely out of his INFINITE kindness! Just what kind of troubles await our hero on this strange, foreign journey? Well, find out on this newest chapter of Kamen Rider Build~!

(Note: Despite what he claims, he's far from a first-rate Caster, yet alone a first-rate Servant.)