2

Get off at Exit C-10 of the Chiyoda Line, in Otemachi Station. Glance at watch, on left hand.

Five minutes left until three in the afternoon. Asuna Yuuki was about to lower her hand when she caught the date in the little windows in the watch face.

Sunday, December 7, 2025.

It was not a special date or anniversary. But something meaningful and emotional filled Asuna’s chest. She raised her head and began walking down Eitai Street in the direction of the Imperial Palace and thought to herself:

Very soon, it’ll be a year…

She didn’t bother to include the other part of that sentence: …since I came back to this world.

Asuna had gone from the iron fortress of SAO to the birdcage of ALO before she was finally freed into reality in the middle of January. What happened to her in the virtual world was slowly shifting from recent experience to more distant memory, but there were moments like this when she was filled with wonder that she was actually in the real world.

The orderly placement of paving stones in the wide street. The rustling of the trees as the chill wind brushed them. The passing crowds, faces tucked into coat lapels or scarves. And Asuna herself, as she passed through this flow.

These were not 3D objects modeled with digital code, but real minerals, plants, animals.

But what did real mean, anyway? If it meant “clusters of atoms and molecules,” then they were no different from those virtual polygons. The polygons were real, they just existed in the memory banks of a server somewhere. The only difference was the type of particles they were.

Was it just a matter of reversibility? Everything in the real world, organic or not, could not be restored to its previous state if destroyed. But objects in the virtual world could be replicated from the same information down to the very last byte.

…No.

That was not necessarily the case. In Aincrad, there had been loss, unrecoverable and permanent. The things that Asuna had touched, felt, gained, and lost in those two years in the virtual castle were undoubtedly real.

But if that was the case…

“…What is the difference between the real world…and the virtual world…?” she mumbled to herself.

“Only the amount of information,” came the answer from right next to her. She jumped up with a start.

“Wh-wha?!”

She turned to see a boy, blinking in surprise.

Longish bangs in front. Slender, fine features with just a hint of sharpness. A plain black shirt with a black leather jacket and faded black jeans.

It was so close to the look of his old avatar that it seemed strange not to see sword pommels over his shoulders. Asuna took a deep breath to sooth the sweet, lonely pain in her breast, and beamed.

“…Oh, you startled me. You came out of nowhere! Did you use a teleport crystal or something?”

Kazuto Kirigaya smiled wryly.

“I didn’t come out of nowhere. I made it to the meeting place just in the nick of time.”

“Huh…?”

She looked around and realized he was right.

The gentle afternoon sun warmed the street and glittered off the surface of the moat. The bridge just ahead led to a heavily guarded gate. They were just before the gate to the Imperial Palace, as Kazuto had suggested. She’d been lost in thought as she walked, and came upon their meeting place without even realizing it.

Asuna’s grin turned shy and she shrugged.

“Ha-ha, I guess I was on autopilot. So, um…hello, Kirito.”

“Better watch out, there’s no nav function in real life. Hey, Asuna.”

Their greetings exchanged, Kazuto suddenly narrowed his eyes and stared at her.

“Wh-what’s up?” she asked, arms crossed in front of her.

Kazuto hastily shook his head and mumbled, “Er, um…well…just thinking, that outfit looks good on you. Makes me remember…”

“Huh…?”

She looked down at her clothes, and in two seconds, Asuna understood what he meant.

She was wearing a coat for the first time this winter: white tweed, with an ivory white knit sweater and a red skirt that sported an argyle pattern.

In other words, she had dressed herself in the colors of the old Knights of the Blood guild. It occurred to her that she’d probably worn that white-and-red knight’s uniform nearly every day in Aincrad. No doubt Kazuto was reminded of those times by her outfit today.

She ran her left hand up and down her waist and grinned again.

“…You’re right. I don’t have the rapier, though. And I can’t help but notice you’ve chosen black for yourself, Kirito.”

He smiled bashfully. “I don’t have the dual blades, though. I usually do a better job of avoiding an all-black outfit, but Sugu washed all of my clothes this morning, so this was all I had to wear.”

“That’s what happens when you let your laundry pile up,” she noted, jabbing him disapprovingly on the shoulder, then slipping her hand around his arm.

“So it just so happens that we’re both in our old colors today. What are the odds?” she asked, looking up just slightly so she could see into his eyes. He coughed gently and answered without much emotion.

“Well, if we keep meeting up regularly for a year, such things will happen eventually.”

“Oh, come on! You’re supposed to say, ‘I know, right?’ not get all logical on me!” She pursed her lips and tugged on his jacket sleeve. “C’mon, let’s not just stand around here all day. It’s going to get dark soon.”

“Um, yeah.”

She sidled up next to him and started crossing the bridge over the waterway.

The imperial gate, white and traditional, was lit by the already reddish western sun, throwing black shadows over the bridge. Though it was a Sunday, the cold weather kept the tourist crowds away.

They passed a police officer in a heavy coat and went through the gate to a little checkpoint, where they took plastic entrance tickets. After the silver fence they were in the midst of a tiny woods so peaceful, it was hard to believe they were smack in the center of Tokyo.

It was Asuna’s idea to go somewhere on Sunday, but it was Kazuto’s suggestion that they meet outside the Imperial Palace gate.

The palace itself was off-limits, of course, but the northeast section of the East Garden, which was within the moat’s ring, was actually open to the public on Sundays—a fact that Asuna didn’t know until today. Naturally, it was her first time visiting. As they made their way along the wide path, she was struck by a sudden curiosity, and turned to the boy at her right.

“Why did you choose the palace as our date spot, anyway? Are you actually a history buff?”

“Um, not really. The main reason was…well, because I was just busy with an errand nearby before this…”

He snorted briefly, remembering something, then returned to his ordinary gentle smile.

“I’ll tell you more about that later, but for now, don’t you think the Imperial Palace is kind of a fascinating place?’

“…Fascinating? How so?” she wondered. He reached out with his right hand and pointed at the thick trees surrounding them.

“It’s about one and a quarter miles north to south, and just under a mile east to west. If you add in Kitanomaru Park and the outer gardens, the total area is about 1.3 square miles, which is twenty percent of Chiyoda Ward all on its own. It’s way larger than the Vatican or Buckingham Palace, though not as big as Versailles. It’s not just the size, though—there are no subways or tunnels underneath it, and a no-fly zone over it. Basically, this is like one giant vertical area of no-entry smack in the middle of Tokyo.”

A map of Tokyo materialized in Asuna’s mind. She spun her finger around in the air absently as she thought, then nodded in understanding.

“Now that I think about it, the major highways around the center of the city are either circular routes or radial routes stretching outward. I guess this must be the center around which they all stretch…”

“Exactly. Tokyo isn’t a grid pattern like Kyoto, it’s a city built in concentric circles. And the very center of it is completely shut off from the rest, not just physically, but also insofar as information. In a way, it’s like the World Tree in the old ALO…oops. Didn’t mean to drudge up bad memories.”

“It’s okay, I’m fine.”

Asuna had been trapped for many months atop the giant tree at the center of that world. She shook her head to show that it was all right and asked, “I understand that it’s physically off-limits…but what do you mean, informationally?”

“Oh, well…”

Kazuto looked around the woods, and briefly pointed out a few spots.

“See the security cameras there, there, and over there? That’s a completely stand-alone security system. There’s a closed network here with zero connections to the outside.”

“Ohh…And they’re rather strangely shaped cameras, too, aren’t they?”

Kazuto’s finger was pointing to a pole, atop which sat a black sphere. If he hadn’t pointed it out, she would have assumed it was just a light pole.

“I’ve heard they’re testing out next-gen security tech here…At any rate, it’s smack in the middle of Tokyo, but it’s also its own little isolated world. That’s a fancy way of putting it, though.”

“Ha-ha, just a bit.”

As they talked, the path wound around an enormous stone wall and rose up a sudden hill. They walked in silence for a few moments and the view opened up before them. Over the wall was an enormous grassy field so large it was hazy. The grass was dried and dead in the midwinter cold, and the trees around it had lost all of their leaves, but it was sure to be a splendid sight in the spring.

“This is where the old Edo Castle used to be. The great hall that you see in all those historical dramas was apparently on the northern end of that grass field.”

“Let’s go see!”

Asuna squeezed Kazuto’s hand and picked up her pace. There were still very few other visitors, and nearly all of them were foreign tourists. On the way, they were stopped by a couple with two adorable blonde daughters, asking for a picture to be taken, so Kazuto politely obliged. The wife offered to take a picture of them in exchange, so they bashfully lined up for a photo of their own.

Once the photo file was sent to their phones, they waved good-bye to the little girls. As the family walked away into the orange setting sun, Asuna heaved a heavy sigh.

“…You tired?” Kazuto asked. She shot him a dirty look.

“Ab-so-lute-ly not! I was just thinking about us being like that in the fut…erm…Oh, forget it!”

Her cheeks burned when she realized what she was about to say, and raced ahead.

“H-hey, wait up!”

She and Kazuto raced a short distance until they reached the little path that split the field into north and south. They found a bench near a fork in the path, and plopped down.

She still had her head turned away from him in a huff. Eventually, he found something to say.

“Well, um…I’m sure Yui would be happy to have a little sister.”

Despite the fresh rush of blood to her face at such a direct acknowledgment, Asuna couldn’t help but chuckle.

“Y-yeah, right.”

“What? Why would you laugh? That’s mean…”

“Ha-ha, sorry, sorry. It’s really a shame that we can’t live with Yui over here, too…”

Yui was the name of a girl they’d met on the old SAO server. In reality, she was just a mental health counseling program—an AI—but she accepted Asuna as her mother and Kazuto as her father. As Aincrad was collapsing around them, Kazuto managed to sneak her core program out in his NerveGear so that she didn’t get deleted with everything else. Now she “lived” in a desktop PC Kazuto had prepared just for her in his room.

But the only way they could interact with her directly was within a full dive—in other words, within ALO. They could contact her in the real world using their cell phones, but that was limited by battery power, and wasn’t the same as being “with” her.

No matter how much Asuna loved Yui as a daughter, and no matter how much Yui loved Asuna as a mother, there was always a wall between them—the wall that separated the real world and the virtual world.

Kazuto suddenly squeezed her hand.

“It’s all right. We’ll be able to live with her someday, once full-dive tech evolves more, and augmented reality functions are commonplace.”

“Yeah…I’m…I’m sure you’re right.”

“As time goes on, the distinction between reality and the virtual world will get even more blurry. The only major wall between us right now is the amount of information…”

She savored Kazuto’s words and squeezed his hand firmly, then looked up.

“You mentioned that earlier, Kirito. Something about the difference between the real world and virtual world being the amount of information. What does that mean?”

“Well…”

His eyes wandered for a moment, then glanced down at their hands, intertwined atop the bench.

“There’s still a difference between holding our hands like this in reality, and doing the exact same thing in ALO, you know?”

Asuna concentrated on the sensation of her left hand.

The pressure of the palm pressing against hers. The warmth that kept away the winter chill. Those sensations still existed between the fairy avatars of ALfheim Online. But even the most advanced full-dive technology couldn’t replicate the adhesion that seemed to suck the skin together, the friction of the fingerprints, and the faint pulse of blood flowing through the veins.

“Yeah, you’re right…You still feel more with your real hands. So that’s what you mean by ‘the amount of information’?”

“Yes. But as the AmuSphere evolves and becomes able to emulate skin sensations and pulsing, what then? Will you be able to tell the difference between a real hand and an avatar’s hand just by touch?”

“I will,” Asuna said instantly. Kazuto blinked in surprise. She stared directly at him as she added, “I’ll be able to recognize your hand, at least. Probably not other people’s.”

In that moment, the temperature of Kazuto’s hand rose slightly, and its pulse quickened. She grinned in satisfaction.

“There’s still more information you get in reality from all the senses, not just touch: sights, sounds, flavors, and smells. So…even if the current AmuSphere gets AR functionality…”

“I know. The instant you see or touch something, you’ll know if it’s real or not.”

AR, or augmented reality, was a feature that would use the AmuSphere to combine digital information with the user’s real vision and hearing. If that became possible, there would be no need for desktop PCs or cell phones anymore. You could display a virtual desktop in front of your eyes, browse the web and send e-mail, even navigate roads and attach info tags to people or objects. The possibilities were endless.

For the moment, RCT and the other major IT manufacturers were hard at work, but there were still major barriers to usability—the electron pulses went out of focus with the movement of the body, extra batteries were required, and so on.

“Sadly, there are people who think constant AR will never be applicable with the current headgear model. But I’m sure that if there’s a breakthrough on the technical end, and we can get massive sensory data here in the real world…we might be able to experience an instant full dive without lying in bed while plugged into a wall.”

Asuna nodded and continued where he left off.

“Then we can cross the wall between worlds and be with Yui all the time. I’m sure that day will come.”

“Yeah, it will.”

Oddly enough, the words they exchanged were nearly the same as what they said after leaving Yui behind on the twenty-second floor of Aincrad. When Asuna realized this, something warm flooded into her heart, and she rested her head on Kazuto’s shoulder.

The promise of that reunion was fulfilled just months later.

So what they said just now was sure to come true as well.

As close as they were to the winter solstice, the sun plummeted behind the trees to the west as if it had been dropped. Birds flocked against the brilliant red sky as they returned to their nests.

Centuries ago, the people living in the castle here atop this vast grassy field must have looked up at the same sunset. Centuries later, freed from the flow of time, would someone look upon the same red sky…?

“Ahhh…”

Asuna murmured, feeling a nostalgic, melancholic urge escaping her breast. Kazuto looked over at her. Their eyes met, and she smiled.

“I think I understand why you brought me here.”

“Uh…y-you do?”

“Yes. If the world is built from the axis of time and the plane of space, then the center of Tokyo, the real world where we live now, is this place right here. And the central axis of the virtual world, which is even now expanding thanks to The Seed, was that old castle. That’s why the color of this sunset feels so nostalgic…”

Kazuto blinked a few times, then beamed widely.

“I see…Yeah, good point. Actually, I hadn’t thought about it that hard. But…what you just said did help me realize one thing.”

“What’s that?”

“The shape of Aincrad. Maybe that spherical cone shape was meant to be a symbol of the axis of time and plane of space.”

Asuna thought it over and eventually agreed.

“Yes…maybe you’re right. But if that’s the case, the world that our guild leader sought to create eventually tapers down to a point and disappears. At least, until a certain someone blew the entire thing up.”

“G-geez, I’m sorry…Vice Commander.”

They shared a silent chuckle. A few seconds later, Kazuto sucked in a deep breath and stood up from the bench, still holding her hand.

“Well, time to get going. This place closes at five.”

“Okay. We should bring Liz and Leafa next time. I bet it would be fun to have a picnic on the grass.”

“Yeah. Maybe in the spring.”

Using his grip to get to her feet, Asuna took one last look at the sunset in all directions.

She wanted to go home. Not to the Yuuki household, in the Miyasaka neighborhood of Setagaya Ward. To their little forest cottage that had temporarily existed on the twenty-second floor of the old Aincrad.

The little log cabin was obliterated in the destruction of the floating castle, but Asuna had a secret plan percolating in her heart. Until that plan came to fruition, the room they rented in Yggdrasil City atop the World Tree in Alfheim was home to her, Kirito, and Yui.

As they walked toward Hirakawa Gate on the north end, Asuna turned to Kazuto and asked, “Can you log in tonight? I want to tell Yui about what we just talked about.”

“Yeah, sure. Is ten o’clock okay?” he answered with a smile. It was soon wiped away.

“What’s wrong? Do you have something else to do?”

“No, it’s not that. I’m pretty sure I can do it tonight, but… actually, Asuna…”

It was rare for him to be at a loss for words like that. He mumbled for a few seconds, but what he said next froze Asuna’s heart with fear.

“…Pretty soon, I might be converting my ALO Kirito to a different game…”

“…Wh-what?!” she screamed. Startled, a few birds took off from a nearby branch.