Shirosaki Reito, a high school student like any other, recently changed schools, since his parents' job forced his family to move to a new town.

He was waiting for the bus on the first day at the new school when something bizarre happened before his eyes.

"Hn…? What's this?"

It was like the very air cracked and shattered: a black rift formed in midair. Reito backed away, surprised and a bit scared, but the rift expanded more and more, as to draw him in.

"W-what's going on…!? I-it's sucking me in!!"

The black rift started pulling Reito, stronger every second. It had become large enough for Reito's whole body to fit in: the boy was relentlessly dragged towards by the darkness.

"T-this is bad…!!"

Reito resisted with all his might, but the rift pulled him in more and more.

Reito looked around, hoping to find someone to help, but there was no one in the surroundings. Eventually, one of his arms was sucked into the darkness.

"Shit…!!"

Reito flailed his arms and legs, desperately resisting, but to no avail: his body completely disappeared into the black rift.

"WAAAHHHHH!?!"

Reito's scream echoed in the deserted bus stop. After swallowing him, the black rift quickly vanished, leaving no trace behind.

The bus stop looked perfectly normal as if nothing happened. The only trace left of the student Shirasaki Reito was his school bag, abandoned on the asphalt.

CHAPTER 1

"…where am I…?"

When Reito came to, he found himself surrounded by a white space.

He looked around, but could not see anything resembling a floor. His body was floating in the air as if there was no gravity in the room.

"W-where's the ground…? No…calm down…take a deep breath…"

Reito felt he was close to panicking, so he shook his head to calm himself down.

He first tried to recall how he went from the bus stop to this place: no matter how much he tried, however, nothing came to mind. When he was absorbed in the mysterious crack he also lost consciousness, apparently.

Then, all of a sudden, a woman appeared before him.

She was a beautiful young lady, her facial features still showing some childish softness, a warm smile on her lips. She looked human at first glance, but also possessed several bizarre features.

Her hair was a bright silver color and she had wings on her back. Not only her hair, but also her whole body glowed.

(A girl…no, an angel?)

The girl's smile deepened, then she finally spoke.

『Honestly, I was so surprised! How many hundreds of years have passed since I last saw a human being? Not to mention, someone so young! It's amazing.』

In contrast with Reito's confusion, the girl's tone was rather laid-back.

After a brief pause of speechlessness, Reito hurriedly spoke up.

"Eh…w-who are you!?"

『Oh, hello there. I should say "nice to meet you", I guess.』

The girl then produced a very polite bow. Reito was still overwhelmed but managed to regain some composure and timidly asked another question.

"…ehm…what is this place?"

『This is the space in between, a place that exists between worlds.』

Reito tilted his head to the side: he couldn't follow the young lady's words at all. She probably realized he didn't understand, so she explained more.

『To be more precise, this is the place that connects the world you were in with another world. It's just like the space between two planets. You were thrown out of your world and ended up here. Oh, by the way, you can't go back to your world anymore.』

"Why!?"

Reito didn't fully understand yet but reacted loudly by reflex. The young woman answered his question, in a very matter-of-fact tone.

『The reason why you can't go back is that all worlds are lined up vertically.』

"V-vertical…what? Isn't Earth surrounded by space…?"

As far as Reito was aware, Earth was one of the many planets floating in space. The young lady, however, continued explaining about rules of nature he had never even heard of as if they were the most natural thing in the world.

『What I mean by vertical is their phase. To use an example from your world, think of a skyscraper. Your world was like one of the floors in the building. You slipped inside a crack and fell to a lower floor, basically. There is a difference with those buildings, though: there are no stairs or ladders between worlds. In other words, there is no way to go back to the upper floor you fell from. By the way, right now you are falling through the space between floors, the space between your world and another world.』

"W-what!?"

Reito was deeply shocked. He couldn't comprehend what the young lady said, after all.

The young lady, however, continued with no regard for his confusion.

『I am tasked with the management of this space in between. My role is to assist those like you, who fell into this space, and send them to another world.』

The young lady stared intently at Reito, who swallowed his breath and finally managed to speak.

"…your role? Could it be that you're a god— "

The young lady interrupted Reito before he could finish his sentence.

『Oh, I am just a manager. Certainly not a goddess or something as grand as that. To be honest, I don't have much to do most of the time, so I usually just peek at the worlds above or below this space, and…ahem. That's enough about me. It's time for you to go to another world, after all.』

"P-please wait a moment!! Is it really impossible to go back to my world?"

Reito couldn't give up just yet, but the young lady's reply was as simple as it was cruel.

『Yes, impossible. Well, it must be quite a tragedy for you, but just consider it as an unfortunate accident. And do your best in the next world.』

"Eeh…?"

Dismayed, Reito pictured his family and friends in his mind.

(I'm going to some new world I know nothing about, without even saying goodbye to anyone…)

A new world I know nothing about…Reito was suddenly attacked by intense anxiety and hurriedly asked a question to the young woman.

"H-hey! What kind of place is this other world?"

『Oh, you have finally accepted it, yes? Hmm, I suppose there is no harm in telling you…』

The young lady smiled happily, reflected for a moment, then continued.

『To put it in super simple terms, it's a fantasy world. Do you like RPGs? In this world, there are real-life monsters, and even species like Elves and Dwarves, you know.』

"Fantasy…"

『Moreover, this world is evolving in a way very different from your former world. Magic is developing instead of science, it seems.』

"Magic…you mean…?"

The young lady smiled and nodded.

『You can use magic, just like this. Ta-dah!』

The young lady had a wand in her hands, out of nowhere. From the tip of the wand, globes of fire and ice appeared one after the other.

Reito was staring, dumbfounded, then the young lady snapped her fingers and the magic globes vanished.

"W-was that magic?"

『Correct. Oh, there is something I forgot to tell you. When you go to the other world, you will keep your memories but your body has to be rebuilt. It's to avoid various inconveniences, you see.』

"Rebuilt…? What do you mean?"

『It's a whole different world, you know. The gravity is different, and for someone who lived in a world of science, using magic could be very difficult. So the only way is to rebuild your body. There's no way a normal person can just warp in a new world and learn magic, just like that… as you see in novels.』

"…wait!! What's going to happen to me, then!?"

Alarmed, Reito pressed the young lady to answer. She seemed to be put a bit on the spot but replied.

『Well, you will keep your memories and your conscience too. The process is a bit random, so you could become something other than a human being, but…it all depends on your luck.』

"After falling in a place like this, I don't know whether I can trust my luck!!"

Reito fervently protested, but the young lady simply smiled again.

『Oh no, please think about it for a moment. It has been centuries since a human being arrived in this space, really. It seems to me like a stroke of very good luck…the devil's own luck, as they say in your world.』

"You can't be serious…"

Reito sighed in disbelief, so the young lady tried to console him.

『Well, you are the first guest I had in a very long time, so I think I can give you some advice. Oh, right! When you want to know something, just call my name in your mind. We'll be able to talk like that. I am in possession of all information about the new world, so ask me anything, all right…』

Suddenly, Reito's consciousness grew dimmer..

"If I can ask anything, then okay…what's your name?"

Reito managed to ask a question in his fading consciousness, and the young lady smiled kindly.

『Airis…the manager of the space in between. If you are ever in trouble, do not hesitate to call me. I'm usually free, so I can answer anytime.』

"…it's a promise."

Those were the last words uttered by Reito to the young lady before everything turned into darkness again.