I felt the gentle sunlight on my skin and opened my eyes naturally. The ceiling was filled with a sky-blue expanse. It was the umpteenth morning I’d greeted in this room, in the city of <AO>. The view no longer surprised me when I woke up, but that didn’t mean I’d grown tired of it either. In fact, I could’ve stared at it forever. But I sat up to check the window that had appeared on the wall sky, stretching as I moved.

I skimmed through the day's schedule, weather forecast, and news headlines summarized in the window, all while slipping into the clothes provided for the day. The garments, delivered daily, were always clean and crisp like new, and yet they melded to my skin the moment I put them on. It amazed me every time. If I asked, maybe they’d let me take a few sets with me when I leave this city—if I ever decide I want to return, that is.

By the time I’d finished changing, lost in thought without any clear destination, the window had vanished, replaced by a view of the city below projected on the wall. According to the schedule, Rio would be coming after lunch. Just thinking about it made the cityscape beneath me seem to shimmer even brighter. What should I do until then?

At present, the only freedom I had extended across a single floor—the 40th—yet there was still so much left to explore.

This place was the high-rise floor of <Nexus>, located at the heart of the city AO. The view was impressive, offering a sweeping vista of the city below. Of course, this wasn’t my home. One day, without warning or sign, I had awoken in this room. Confused and disoriented, I’d been "taken in" by Nexus operators who appeared to have been waiting for me. Since then, I’d spent peaceful days here. The room they gave me was far more comfortable than my previous living space. And above all—

“It’s amazing this isn’t even a real window...”

I reached out and gently touched the vast scene on the wall. At my fingertips, ripples spread, and the view outside disappeared, replaced by a dull gray wall. The texture that met my skin wasn’t the smoothness from moments ago, but a faintly rough, stone-like surface. Both the earlier cityscape and the gray wall were just projections from the information display membrane—<Cherubim>—installed in the walls. The shift in texture was made possible by haptic feedback technology. But no matter how long I stared, I couldn’t tell it was just an image.

When I touched it again, the wall returned to showing AO’s scenery.

There were still so many things I didn’t understand. One of the operators once explained that Nexus was the organization in charge of managing and operating the entirety of AO, responsible for all policies concerning citizens' lives. I vaguely remembered institutions like that from my world too, but why was I given a room here?

The texture of the clothes I received was like nothing I’d ever felt, and the meals delivered daily by the operators always looked unfamiliar—sometimes even including mysterious ingredients. Last night, I tried a drink with trepidation, unsure whether it was tea or fruit juice. And yet, it felt so perfectly made for me. I should’ve asked what it was.

When I opened the fridge, I found several bottles of that very drink inside. One of the operators must’ve been thoughtful enough to stock it for me. I twisted off the cap and took a sip. Still delicious. The plain gray container looked like something from outer space.

At the moment, there were only two things I knew for sure. First, that this was a different world—one where the city called AO existed, unlike the world I came from. And second—

“Welcome to AO. I’ve been waiting for you.”

Rio’s words on the day we first met. My arrival in this world—this city—wasn’t a coincidence. It seemed there was a reason behind it.

“Hmm, but that’s not really much different from knowing nothing at all, is it...?”

As that very rational doubt began to rise in my mind, I spotted a couple jogging through a park beyond the window. I’d never been into exercise before, but running through such greenery looked refreshing. Someday, if I could go outside…

“That’s right,” I murmured, remembering suddenly that I needed to go to the training center. If I could get my health score—the one they measured—to the required level, I’d be allowed to leave Nexus. That was the promise I made with Rio. Maybe because I’d led an unhealthy lifestyle before, my numbers had steadily improved. I was almost at the target. If I pushed a little harder, I might even hit it this morning.

I had to change into my workout gear—even though I’d just changed clothes. Annoying. Just as I thought that, my reflection appeared on the wall—it had turned into a mirror. I was already dressed in sportswear. Maybe I’d been so sleepy when I got dressed that I forgot. Still, it felt like a lucky break, and I headed to the center with a light step.

I never imagined moving my body could feel this good. Toweling off my damp hair after a shower, I felt a quiet sense of achievement. My skin was firmer, my hair glossier—since arriving in AO, I looked like a whole new person. I didn’t work, was provided with meals and a comfortable place to live, and the only thing required of me was regular, light exercise. No wonder I was getting healthier by the day.

Even an optimist like me occasionally felt a twinge of unease. It was almost like being in one of those fairy tale houses made of candy... But any such worry vanished when I changed into fresh clothes and welcomed Rio into the room. He never knocked—he always entered at the perfect moment.

“You finally hit the score. Congratulations.”

That was the first thing he said, his voice gentle. “Thanks, Rio,” I replied, my lips curling into a smile without thinking.

The white outfit that framed his tall figure was unlike anything from my old world. Composed of several geometric layers, it gave no clues about his profession. The intricate design only added to the sense of mystery around his intelligence.

“I already know,” he said, pointing at his left wrist with slender fingers—toward the bangle-shaped device.

“Oh, right. The <Being>...”

I looked down at my own left wrist. According to Rio, it was a bracelet-style device that "supports the health of AO citizens from every angle and ensures sustainable well-being." It didn’t have a display. Instead, its milky-white surface glowed softly, and if you looked closely, you could see tiny stardust swirling inside. Rio said the complex pattern formed by the stars was a visual representation of the user's genetic algorithm, constantly shifting like an amoeba, dividing and converging endlessly.

“You’re not very surprised by the Being, huh?”

“I used a similar device back in my world,” I replied.

There were no seams on the Being. It adjusted to the wearer when put on, shrinking to fit and hardening gently around the wrist. I’d gotten used to it, but it really was amazing technology. And the fact that all AO citizens had one made it feel all the more significant that I had one too. I stroked it fondly. It felt like proof that I was allowed to be here, at least for a little while.

“But there are still a lot of other things that surprise me.”

“Like the Cherubim?”

I nodded, glancing around at the panoramic view on the wall.

“More importantly, you promised, right? Once I hit the score, I could go outside.”

“Of course I remember. Let’s go now. The weather’s nice, too.”

“Yay, thank you!”

Up until now, I’d only been able to see AO through the Cherubim. To actually walk through this unknown city—I could hardly imagine anything more exciting.

“But I’ll be going with you,” Rio added, smiling at me.

“Fine by me. But... aren’t mentors supposed to be busy?”

I was shocked when I first learned that Rio—who didn’t look a day over his late twenties—had built and now maintained most of AO’s urban systems on his own. The operators working in Nexus often called him “Mentor,” a title I wasn’t familiar with but could tell was important. Despite that, I often found myself speaking to him like an old friend. Why was that?

“This is important work too. It’s all part of making the city better.”

His teal eyes met mine with a quiet intensity. Embarrassed by his gaze, I changed the subject.

“Anyway, isn’t it about time you told me why you brought me here?”

“You may have heard this before,” Rio began, “but there are distortions in space-time at certain points. Sometimes, those distortions connect to another place... an 'outside world.' In fact, quantum entanglement uses those paths to transmit information. Through that data, we realized your world and ours were linked. Clarifying that theory, and amplifying that connection for just a brief moment to bring you here—that’s what our next-generation transport mechanism, the Universe Metric Distorter, or <UMD>, was designed to do.”

With a flick of his left arm, the Cherubim displayed the theoretical framework behind the device. I let out a loud sigh.

“Come on, Rio. What I’m asking about is the reason, not the process. You know that.”

“Sorry. I just enjoy talking about this kind of thing.”

Maybe that was true. I certainly looked forward to talking with him. Even though my needs were all met here, I was still a foreigner in this world—someone from a place without AO. No one here knew me, except for Rio. I remembered how happy Robinson Crusoe was not when he found food, but when he met FRIDAY.

Even putting aside my unusual circumstances, I genuinely enjoyed talking to Rio. His explanations of AO were a window into a completely unknown world. But more than that, something about the way he spoke drew me in. Complex systems became clear when he described them. His intellect was deep, and his sincerity radiated like the calm of a still ocean. I liked watching the shadows of his lashes fall across his cheek when he paused to think. Even when he dodged questions or teased me, like before.

Still, that was just how I felt. Rio probably had plenty of other people to talk to. Wasn’t he bored talking to someone like me?

“The reason I brought you here... I’m sorry, but I still can’t tell you.”

“You’re the one who brought me, though?” I said with mock irritation.

“A bit selfish, don’t you think?”

I’d been dragged here without warning—I figured I was entitled to a little sass. Rio looked at me seriously.

“Do you want to go back?”

“Eh... well, I mean, you said you were the one who brought me here…”

I trailed off, my tone becoming defensive even though I had nothing to feel guilty about. I remembered his words from that day again: Welcome to AO. I’ve been waiting for you.

Was it foolish to cling to such a simple phrase for comfort in this strange world?

No... deep down, I already knew. It wasn’t that I didn’t want to go back. If Rio told me to, I would return immediately. I just... wanted to postpone it. —Postpone what, exactly?

“More precisely,” Rio said, pulling me from my thoughts, “it’s not so much that I brought you here... It might be more accurate to say that the city itself needed you.”

“Huh.”

So he had thought seriously about my petty, half-accusatory words. That made me feel a little guilty.

“The city needs me? AO does?”

What did that even mean? I tried saying it aloud, but Rio just stared out at the Cherubim’s projection and said nothing.

Oh well. If he wasn’t going to explain now, then maybe it didn’t matter just yet.

More importantly, today was the day I finally got to go outside.

Almost as if he read my mind, Rio turned to me.

“Don’t worry—I’ll tell you everything important in time. But first, you need to see AO for yourself.”