It was a hypothesis that had been reinforced by attempts across the years.
Nanahoshi Shizuka could not return home until a certain event had come to pass in the future.
Since the time she last saw Rudeus, Perugius and his familiars had worked in tandem with her leftover research to attempt to resolve the issue preventing her teleportation device from operating.
But the result was the same.
An unknown force culled the spell before it could reach completion. At the same time, the magic circle used cracked, splintered by an unknown force.
And so Shizuka... 'Nanahoshi' waited.
So as to not contract another unknown disease and risk death, she remained frozen in time, waking up less and less across the years so as to preserve her life.
And like that, the world moved on, time racing past in the blink of an eye.
The acquaintences from the past grew old and vanished. Her friends slowly disappeared one by one as well while their children grew up.
Zanoba, Cliff, Rudeus...
One by one, they vanished. Even Rudeus, who Nanahoshi thought might be crazy enough to develop a magic spell to extend his life so as to not leave Sylphy and Roxy behind.
But Nanahoshi endured.
It was lonely, but in the end, this wasn't her world.
Her life was back on Earth and with Akito. Although it was sad to have all her friends vanish, that was going to be the case anyways once she left.
So Nanahoshi waited.
The only constant in her life was Perugius, who continued to search for a solution to the problem she and Rudeus faced on that day and gave her routine updates every time she awoke.
That was the fate of the Silent Seven Stars. Slumbering in frozen time and waking only to find the world had passed her by while she waited for a miracle.
...No. It was an inevitability.
Even though it seemed unlikely. Even though it seemed like she was just trusting in the future that might never come to be like those people who put themselves in cryostasis.
Nanahoshi waited. Rousing to take her medication and hear just how much more the world had changed since her last awakening. Living a life that seemed more dream than reality.
That day, she roused from her slumber again. Like always, she slowly opened her eyes and took in the bleary room.
A pristine marble room of pure white, reminiscent of a hospital room. Golden torches illuminated the surroundings while large windows showed the endless skies.
A view that sometimes made Nanahoshi question if she hadn't already died and gone to heaven.
But after a few moments, the familiar gnawing hunger from the after effects of timestop started and she got a grip back on reality.
Taking a deep breath, she blinked away the fatigue and turned around to look at Sukeakoto and thank him as usual.
But the familiar masked man was missing.
"...Huh?"
Nanahoshi blinked and realized that it wasn't just him missing.
Miss Sylvaril was usually there with a fresh meal to help Nanahoshi and Sukeakoto recover. But the familiar golden-haired woman with her bird mask was nowhere to be seen.
Instead...
"So this is what Stella looked like before she was reincarnated, huh?"
A voice that Nanahoshi could never forget. But at the same time, an intonation far too different from the one she remembered.
Nanahoshi blinked and rubbed her eyes, wondering if she wasn't dreaming.
It was a vivid memory still fresh in her mind. Sylphy and Roxy showing up to tell her that Rudy had passed away. That they thought she should know, being the last of their friends still around.
Nanahoshi remembered that. She remembered it clearly. The anguish and grief in their eyes that made it evident it wasn't a prank or mistake.
But... the man standing in front of her...
Familiar light brown hair. Clear green eyes. An annoyingly handsome face that was wasted on a pervert like him. A fancy grey robe just like that guy had taken to wearing after he joined up with Orsted.
Rudeus Greyrat. Rudy.
The man who gave his life to pull herself, Akito, and their friend Seiji out of the way back on Earth and was reincarnated here.
A dear friend to whom she entrusted her future.
It was impossible for him to be there. He was dead. And even then, he wouldn't have appeared like that, still looking like he did when they first met.
And when that sliver of doubt appeared in her mind, Nanahoshi saw reality for what it was than what she thought.
...Yes. It wasn't him. Although the man looked similar, he was too different. Too many subtle differences that added up to a clear divergence.
Instead of a staff or the magical prosthetics, the man had a sword. The robe she thought was grey turned out to be a pure white cloak over a pristine white uniform with a fancy 'R' embroidered over the chest.
The familiar light brown hair turned out to be white as well, only appearing brown because of the torchlight. And those emerald eyes weren't the familiar pure green, but were mixed with gold. Not only that, the pupils were wrong. Normal instead of the changed ones he should have from his Demon Eyes.
Even so, Nanahoshi thought the man looked too familiar. Even if it was a descendant, that guy just looked way too close to Rudy. Like a palette swap in a game or something instead of a different person.
"Ah." The Rudy look-alike shook his head and said, "Sorry. This is probably a shock, all things considered." He let out a warm smile and said, "I promise it'll all make sense soon though. ...Probably."
A calm and casual demeanor. But also one filled with confidence.
Different from the somewhat awkward air that Rudy had.
That realization was enough to finally draw Nanahoshi out of her thoughts and take stock of the situation.
Specifically, the fact that her caretakers were gone and the one to greet her was someone who had the face of a dear friend long departed.
Nanahoshi immediately raised her arm, priming the various magic rings she wore for self-protection. "Who are you? And how did you get here?"
The man chuckled. "Who am I? Mm... That's a complicated question to answer. The same with how I got here. If we went into detail, we'd probably be here all day. But to keep it brief..." He smiled and held out his hand. "My name is Rudeus Notus Greyrat, visitor from another world. Although it's by chance, I've a lot to talk with you about, Shizuka-chan. Specifically..."
After saying that, he shifted into Japanese and continued. "I want to confirm and revise a few of the hypotheses and theories you worked on with Rudeus and Perugius about returning to Earth. You see, I believe you've all missed a crucial piece of the puzzle... Not that I blame you." He laughed and said, "It's one that was left in a different box, after all."
Nanahoshi stared at the man... At 'Rudeus Notus Greyrat.'
The fact that he spoke Japanese gave him some credibility. The fact that he specifically mentioned 'Earth' added more. But even then...
No.
Although this could potentially just be a fever-induced dream due to a flare-up from the Mana Drain syndrome... especially since it made zero sense, she had to acknowledge even the slightest possibility it might not be.
That this was reality, and that she was truly meeting a Rudeus from a parallel world who had somehow reached her in the distant future.
Nanahoshi was hesitant.
There were still too many odd points. Like how Perugius wasn't here and how neither Sylvaril or Sukeakoto were here either.
Not to mention the fact that this Rudeus was so *different*. His physique, demeanor, and mannerisms reeked of a person used to standing at the forefront of power.
Similar to Orsted and Perugius.
And Nanahoshi was concerned too about Hitogami. If this might be a ploy by turning her into one of his apostles using a vision of Rudy.
But...
*RUMBLE*
A loud and roaring growl from Nanahoshi's stomach.
She froze and felt her face heat up. Clutching her belly, she desperately wished that she still had her familiar mask on to hide behind.
Especially when that guy started to laugh.
Nanahoshi glared at the man.
"Sorry." The man calling himself Rudeus Notus Greyrat chuckled and said, "You're definitely her. A bit grouchier and more cautious, but there's no mistaking it."
Nanahoshi gave the man a blank stare and said, "...Pleased to meet you as well."
The man... Nanahoshi decided call him 'Notus' to distinguish him in her mind.
Notus smiled and then waved his hand.
The moment he did, a table materialized out of thin air, stocked with platters of fresh sashimi, rice balls, and a bowl of what couldn't be anything else but miso soup.
Not only that, but there were some soda cans, donuts, pizza slices...
Nanahoshi blinked and then said, "...I must be dead." She slowly walked towards the table and picked up a soda can, tilting it back and forth. She cracked it open and watched it fizz before looking at the other food. "...That's the only way this makes sense."
Notus laughed and said, "If that's throwing you for a loop, just wait until we start talking multiverse theory."
"What?"
"Exactly."
-N.S-
Nanahoshi had a massive headache.
On the bright side, she didn't feel the usual gnawing ache inside her body from the Mana Drain syndrome.
But on the down side... NOTHING. MADE. SENSE!
Notus chuckled and reached out as if grabbing a cup. And the moment he did, a glass of what was definitely coffee from the smell, color, and steam emerged. "Don't think about it too hard, Shizuka-chan. Your head might explode."
Nanahoshi narrowed her eyes and said, "Don't call me that. Just call me Nanahoshi."
Notus chuckled and said, "Right, right. Bad habit."
Nanahoshi felt her eye twitch and then took a breath to calm herself.
They were still in the room where she usually woke up from her stopped time. That sterile white room at the bottom of the sky fortress.
Except, now there were a pair of plush modern lounge chairs in the middle of the room, along with a small coffee table between them.
After some prodding, it was where Nanahoshi and Notus were seated to have their in-depth conversation.
Chic, modern furniture.
Furniture that Notus had pulled out from thin air in a way that WAS IMPOSSIBLE.
It defied the laws of physics! You couldn't create matter out of nothing like that! And even if you could convert mana into matter or magic it, there was NO WAY that he could do it instantaneously like that without a chant or magic formation!
"Huh." Notus sipped on his coffee and said, "You two really are similar... Here." He reached out to set something down on the table in front of Nanahoshi.
Nothing was in his hands, and nothing was on the table. But the moment that he stopped moving his hand, a steaming styrofoam cup of hot chocolate appeared.
Instantaneously. Not piece by piece, but wholesale as if it had been there the entire time.
Notus smiled and said, "This should help you calm down."
Nanahoshi gave Notus a blank stare and said, "I can't have anything with mana in it."
Notus tilted his head and said, "There isn't any mana in that." He paused and said, "Well. It's technically made *from* mana. But that mana's been converted into raw energy and twisted back into atomic matter before recomposited into corresponding molecules and materials."
"...What?"
Notus waved his hand and said, "Don't worry about it. And besides, I don't know what weird disease you have that's preventing you from incorporating mana into your body, but as long as I'm here it can't do anything to hurt you."
A completely self-centered and arrogant statement. One that felt like it had no basis whatsoever.
...But seeing as Perugius hadn't showed up to stop him, that meant he was either an accepted guest.
...Or strong enough to have defeated Perugius, which meant that Nanahoshi didn't have a choice in the matter anyway.
After a bit of thinking, Nanahoshi sighed and picked up the cup to take a sip.
Even if it was poison, at least she could enjoy herself a bit first.
A warm and familiar taste. Smooth chocolate and just a bit of cream. Not too sweet, not too bitter.
Nanahoshi didn't drink much hot cocoa back on Earth, but if she did, she imagined this would be the perfect blend for her.
...Which was strange, considering that she had never met Notus before.
And that was the other thing.
Nanahoshi set her cup down and then frowned, staring at Notus. "You said you were from another world. I still haven't decided whether or not to believe you on that... but assuming that's the case... Is there a 'me' in your world as well?"
It was the only way that made sense.
Notus kept referring to 'her' and how 'she was similar.' And in a close and familiar way too.
Not like a friend.
...Did that version of her fall for him or something?
And he had called her 'Shizuka-chan' as well...
Notus chuckled and said, "You could say that. She's not 'you' like you are now, but I definitely know a version of you very well."
Nanahoshi's frown deepened and she said, "Do you enjoy being purposefully cryptic?"
Notus smiled and said, "A little. I can see why Pierre does it now."
"Who's Pierre?"
"It's complicated. But in any case..." Notus held up his left hand and stared at his wrist. And the moment he did, a wrist watch popped into existence.
Again, made zero sense. But Nanahoshi was starting to become numb to the fact that the man seemed to be breaking all the known laws of physic and magic.
"Mm... we're running out of time, so I'll get to the point then." He looked at Nanahoshi and said, "To directly answer your question, yes. You're my baby sister, actually, 'Shizuka-chan.'"
Nanahoshi froze, mentally parsing that latest bit of information.
She... was Rudy's baby sister in another world?
...It was possible. She *did* hypothesize that there was a chance she had been reincarnated like Rudy, but simply died as an infant without gaining her bearings.
But then again, she had her physical body here. And she hadn't died... At least, she didn't think she died?
No, Rudy said that he saved them, and she remembered being pushed out of the way.
But then...
...Was that 'Shizuka' that Notus knew actually her?
It would explain why the transportation circle failed. If her soul was split across time, then it was impossible for 'her' to return to Earth.
It would also explain why her body didn't change. Perhaps it was the soul's memory of the physical form causing a matching body to exist?
And yet, that didn't account for the fact that she could get sick.
But-
"Okay. Definitely the same person... But you can relax, Shizuka-chan."
Nanahoshi blinked, snapping out of her train of thoughts. And then she frowned and said, "What do you mean? If that's true, then it changes everything."
The reason why she couldn't go home. The reason she was stuck in this ageless body. The reason why the future seemed to be changing the past...
Notus shook his head and said, "I'm not sure what you're thinking, but if it's something along the lines of having your soul split, that's wrong."
"...And you would know this how?" Nanahoshi crossed her arms and said, "I've tolerated a lot, but unless you have concrete evidence on this, you will have to excuse my disbelief."
Notus hummed and said, "I 'could' show you, but my gut's telling me that messing around in this time too much is gonna bite me in the butt. At least right now..." He rubbed his chin and said, "...I can tell you that my baby sister got properly reincarnated since she vividly remembers getting hit by a car and splattering. Well, she didn't tell me that, but judging from the PTSD she has with blood and viscera splatters, that's probably the case."
Nanahoshi paused to consider that. But then she shook her head and said, "Even then, it doesn't eliminate the possibility."
Rudy recalled saving them, and Nanahoshi recalled being pushed, but that was it. After that, she had found herself in this world.
But there was definitely a small gap. It was possible that she had died and lost the memories due to trauma.
"Mm..." Notus nodded and said, "True. Hm... what did Rudeus say to me again...? I think he mentioned a bit about the divergence between us too... Ah." He smacked his fist into his palm and said, "Right. You were saved by the 'me' in this world before you got isekai'd- No, 'tripped' into this world, right?"
"...Yes?" Nanahoshi slowly nodded and said, "I have a question on what you mean when you said Rudeus spoke to you, but continue."
"Well. That didn't happen to my baby sister." He placed his hand on his chin to think and then said, "...I think she mentioned she had a fight with her boyfriend or something that day... Akito? Akihito? Something like that."
Nanahoshi nodded.
It was the same then. So-
"But then he got mad and stomped off. At that time a truck ran past a red light, so she ran forward to push him away. As a result, she died while he lived."
-Eh?
That... wasn't what happened?
Nanahoshi remembered that she was the one who got mad, and then protected by Aki as the truck came. But... that version of her protected Aki?
Notus tilted his head and said, "Judging by your expression, I think you believe me now?"
Nanahoshi sighed and said, "Believe? No. But I'll accept it as a plausible explanation."
"Great. Then let's talk about parallel universes."
"...I beg your pardon?"
"Come on, we won't be getting anywhere at this rate without that baseline. It won't take long... And I also want to pick your brain a bit about theories. I'd ask my baby sister, but she's still a toddler so her brain isn't up to task even though her mind is. Oh, and we should probably talk about Hitogami too and the possibility of divine power crossing multiple dimensions as an extradimensional constant or phenomenon. Maybe souls as well..."