Shiori-san.
Sou-kun...
Is Kaori...
It seems her condition has stabilized.
I see.
But...
They said that there's virtually no hope that she'll ever wake up.
"Episode Nine 'Gateway to the Past'"
At that point, the planetarium café was the last thing on our minds
and ultimately,
we ended up doing nothing for that year's school festival.
Immediately after that,
Nagisa-senpai let us know that Yui Furukawa had transferred away.
Ooh, I found you!
Hey, you should at least show up to club every once in a while.
Sorry.
The class dean was worried
and asking about your career choice, you know.
Oh, yeah, that...
Sou, I understand how you feel, but you need to switch gears.
Yeah...
Speaking of which, what did you decide to do, Prez?
I've chosen the Department of Science at Uchihama U.
I recommended it.
Nagisa-san.
I also intend to do whatever I can.
What will you do, Sou-san?
I...
In order to find a way to make Kaori better,
I set my sights on studying medicine.
"Letter of Acceptance" "New" "Medical Dictionary"
Shortly after I was accepted into medical school,
I left the house where my memories with Kaori lingered.
At the university, I immediately ran into a wall.
Brain research was vital to bringing Kaori back around.
But I came to the hard realization that modern medicine was limited
by its focus on the treatment of symptoms.
The brain is unknown territory.
Other parts that are injured can be artificially replaced
"Frontal Lobe" "Hypothalamus" "Optic Chiasm" "Pineal Body" "Medulla Oblongata"
or, in theory, even possibly regrown,
but for the brain alone, that's impossible.
You know, I'm doing research on quantum Turing machines right now.
Quantum Turing machines?
Don't you remember that teacher in high school,
who used to ignore the course material to ramble on about whatever?
Sure.
"Cat" "Box"
Back then, I thought that the stuff he talked about didn't make any sense,
but essentially, my research is about getting that off paper and into practice.
Well, to put it simply,
the idea is that maybe the brain is a quantum Turing machine
or something along those lines.
The brain?
Ready to grasp at straws, I got into quantum theory
and even into a field called quantum cybernetics.
It was only later that I found out
that it was deeply related to Shiori-san's field of research.
All I'd heard was that since Kaori's accident,
she had immersed herself in some kind of special research.
Several years passed, but Kaori remained unconscious.
Sou, if you're home, I'm coming in.
Depressing...
"New" "Medical Dictionary" "Absolute Cure!" "Pharmaceutical Affairs Law"
Again?
I'm borrowing your kitchen.
Kenny sent over another new report.
What was it again?
"Reverse Time Travel by Extending Cosmic Strings
into Extra Dimensions," I think it was?
Talk about a pipe dream, you know?
It's basically talking about traveling back in time, right?
Even if that were hypothetically possible...
Those time paradoxes? No one knows how they'd occur, right?
It's from Nagisa-san.
Ah! My dear old alma mater.
But why are you building a new research lab here?
There's nothing really wrong with the current location, is there?
I wonder if you remember, Airi-san.
About that black box that I often brought to the club room?
I do...
That box has been the subject of research since back then,
but as it was studied,
it became clear that it responded strongly to a specific place.
Respond?
Yes.
And that place is here?
That's right.
Why is that?
Not to mention, demolishing the academy just for the research?
Isn't that overkill?
Would you two give me a little more of your time?
Sure... I don't really mind...
What is the nature of this place?
Hanamiya General Research Laboratory.
This is where we're doing the research on that black cube.
We're involved in various other fields as well,
doing globally cutting-edge research.
Shiori-san...
Long time no see, Sou-kun.
You, too, Airi-san. Welcome.
It's been a long time.
Shiori-san, is that thing ready to see right away?
Yes.
What's this place?
It's where the lab's top secret research is conducted.
Which means, Shiori-san is...
Yes, I'm a member of that research team.
What in the world are you researching?
As for that...
It will be faster if you see it for yourself.
Wow, this is kind of amazing...
It's practically science fiction.
So, the thing in the center is top secret?
That's right.
--Yui... --What?
Is that... Furukawa?!
Huh? What?!
Yes.
That is Yui-san.
Or no, perhaps I should say, it's what used to be Yui-san.
Why? What's Yui doing here?
Yui-san was...
On that day, the day Kaori-san was in that accident,
I returned home to find Yui-san asleep.
Perhaps, to be precise, I should say that she had ceased to function.
Yui-san, I didn't know you'd returned home.
Today was a terrible day, you know.
Don't make me worry so much...
What?!
It can't be...
Sakunoshin! Sakunoshin!
Please! Come quickly!
Kaori said that she'd lost this...
Why did Yui have it?
I don't know.
Whether Yui-san was related to that accident or...?
But why is this top secret?
She is...
...not human.
--What?! --What?!
Not human?
To put it simply, she's an artificial human being.
An artificial human being...
She is something we could never build with our current technology.
Who built such a thing?
Why did it appear at Uchihama Academy
and then suddenly cease to operate?
We have nothing but questions.
But why have you kept this quiet until now?
Back then, there was the incident with Kaori-san
and I didn't have the courage to tell everyone about this.
I'm sorry.
And there was one other reason.
Because the black cube, which our research team calls the AI Unit,
responded to Yui-san.
Yui and that box... How in the world are they related?
But as we studied her,
I found one possible way to save Kaori.
A possible way to save Kaori?
How...?
Yui-san's artificial vital systems turned out to be flawless.
Internal organs, blood vessels, nervous system, and even the brain.
--The brain... --That's right.
Her brain has the functionality to equal that of a human brain.
Then, the way you thought to save Kaori is...
We study her body and build a new body.
And then, we transfer Kaori to it.
Transfer Kaori...
All the information in the brain.
We'd transfer it all over, including her consciousness.
A quantum Turing machine...
But that's...
Is that even theoretically possible?
I would like your help on this research from the two of you.
Airi and I dropped out of university to join Shiori-san's team
and we began the research needed to build a new synthetic body.
It was named the Yui's Unforced Intelligence system.
The YUIs Project.
Airi mainly worked on the AI Unit.
And I studied Yui's body.
The technology used to build Yui's body was astonishing.
Our research progressed rapidly.
Several more years passed
and we finally completed a new artificially-made synthetic body.
The time has finally come.
Yes.
We will now conduct Kaori Sasaki's transfer of consciousness.
Please begin.
Connecting interface.
Quantum oscillations confirmed.
Commencing quantum entanglement.
Brain waves, normal.
Heart rate, normal.
The synthetic body's functions have begun to go active as well.
Huh?
What's wrong?
I don't know, but...
Um, the information isn't transferring over
to the synthetic body's artificial brain.
Why not?
Wh-What should we do?
This can't be...
It wasn't supposed to be like this...
Stop the machine! Cancel the transplant!
Quantum entanglement disengaged.
What could this be?
What is it?
Kaori-san's consciousness hasn't been transferred,
but the synthetic body shows signs of an active consciousness.
The experiment?
Is a failure.
We can't use this synthetic body for the transplant anymore.
Sou, is it true that Shiori-san is going overseas?
Yeah.
There's apparently a place in Northern Europe
where they're researching artificial brains.
I see.
So, Shiori-san hasn't given up yet.
But as for that method...
Yeah.
Now, then, I'm going back.
What do you suppose those two are going to do?
If Akiyama-kun doesn't arrive at a conclusion soon,
it's going to be sad for Hasekura-san.
After all, Akiyama-san's thoughts have been so consumed with Kaori-san
that it didn't seem like he's noticed Hasekura-san's feelings for him.
I'd thought the failure of the experiment was a good place to stop, but...
It's not so easy,
that's the nature of a relationship between a man and a woman.
That's why the three-dimensional world is a pain.
Right, Hiro?
"Reverse Time Travel by Extending Cosmic Strings
into Extra Dimensions..."
It's basically talking about traveling back in time, right?
Traveling back in time...
She is something we could never build with our current technology.
Impossible technology...
You know, I'm doing research on quantum Turing machines right now.
It can't be...
...that black box that I often brought to the club room...
...but as it was studied,
it became clear that it responded strongly to a specific place.
This is absurd.
It's ridiculous!
It should be ridiculous, and yet...
What's up with how neatly it all adds up?
Hasekura-san.
Alone again today?
Yeah, I guess...
Is Akiyama-san still keeping himself locked away?
What in the world could he be doing?
Wake up, Sou.
Kaori...
Wrong.
Oh, it's you, Airi.
Are you always sleeping in places like this?
Got a problem with that?
It's not really a problem, but you're going to destroy your health.
Oh, this is perfect.
There's something I want you to see.
Hm? What is it?
"Test Tank 5 (2 Tubes)"
Why...?
What in the world do you think you're doing?!
Kaori's synthetic body has been...
...made into Yui...
It's been remodeled to look like Yui's body?
We're going to change the past and save Kaori.
Change the past?
We'll send Yui to right before Kaori gets into that accident
and have her stop the accident.
H-Hold on a second.
Don't tell me you're talking about time travel
and that kind of fictional stuff?
Wha...?
This is...
...the paper by that researcher over there that Kenny sent long ago?
--Yeah. --This is just a theory
--without a shred of proof to back it up.
You seriously believe in something like reverse time travel?
Yeah.
Even if this were hypothetically real,
and Yui were to change the past, it would only make the world diverge.
It doesn't mean that the current Kaori would be saved.
After the world diverges,
there's a chance it'll merge back together again.
Merge back?
The chains of fate would rectify the world
and the paradox would eventually vanish.
The chains of fate...
Airi, every time a physicist conducts that cat experiment
in some corner of the world,
the physical quantity of universes doubles...
Do you really believe that?
B-But that's the many-worlds interpretation, right?
Considering the entire universe's overwhelming material resources,
they're glitches that can be cleared up within just a couple decades.
Once the report becomes lost and the experimenter's memory vanishes,
the world will merge back together.
In order to make efficient use of resources,
a force will exerts itself to once again merge worlds that have diverged.
That's nature's law.
And that's what you're calling the chains of fate?
B-But in order to go into the past using that method,
you need a quantum oscillation device on the other side, too...
You don't think...
The AI Unit?
That cube generates minute quantum oscillations at one specific location.
And where it responds most strongly
is here,
where the elevator was on the fifth floor of the old school building.
The location where Yui appeared...
That's right.
What is Yui to begin with anyway?
Created with impossible technology,
she suddenly appeared
and responded to this black box, the AI Unit.
What was she there for?
What was her goal? Her motivation?
Did she really have amnesia then?
Thinking back now,
even her incomprehensible actions all add up if my hypothesis is right!
Sou, are you... in your right mind?
Who knows?
Sou... Airi...
Listen, Yui, this is a ball.
A ball.
Ball.
Then, what's this?
Ball?
So close! This is a globe.
Globe... Globe?
Yes! A globe!
Come on.
Left. Right. Left. Right.
Sou, this is dangerous. This is very dangerous.
It's okay. It's very okay.
The air is clear today.
The starlight that we see from the Earth's surface
is light from long, long ago.
For example, take a look there.
The distance between the Andromeda Galaxy there and Earth
is 2.39 million light-years.
What we're seeing now is light that's a whole 2.39 million years old.
Compared to 2.39 million years,
fourteen years is just the blink of an eye.
The more time passes, the more distant the past becomes,
increasing the amount of energy we'll need.
Based on the simulations so far,
the loss is greater than we'd imagined.
"Running..." "Please wait..." "Suspend" "Cancel"
"The program has failed to run." "Display Details"
Why...?
I see the twilight has you in its thrall.
Why won't it work?
Hey, Sou, who do you suppose made the very first Yui?
The AI Unit.
What?
Ultimately, in the beginning, analyzing that cube, we...
Or no, I think Shiori-san may have created her.
Then, what about the AI Unit?
I don't know.
That quantum Turing machine
might be something like the Akashic records,
meant to record data on the many worlds.
Which is exactly why it responds only to Yui, who is the point of divergence,
and permits no one but Yui to travel time in reverse,
serving as her save point...
That's it... A save point!
Yui.
Yes.
I'm going to send you into the past now.
Yes.
Your job is to save Kaori Sasaki from the accident
that happens on October 14th.
Yes.
Yui, I...
Sou...
I'm sorry.
Maybe we should go see what's going on.
I agree.
I'll hold down the fort here.
All right, then let's split up and check things out.
Uh, then I'll go upstairs.
Sou-kun?
Sou-kun, what's wrong?
Kaori...
Many times over, in my heart
I expressed my love for you
Will my sentiments remain?
Though I disappear?
Your voice
Your honest eyes
The warmth I'll never forget
I want to lock them away in my memory
The things that can't be changed, I want to change for good
Living out my destiny as many times as it takes
Laughing together, joking together
"I'll see you again tomorrow, right?"
Surely...
I want to see you
If I'm to be granted just one wish
How many times has it been for me since then?
--I heard there's been another case...
--I want to tell you everything right this minute. --in the neighborhood.
--Open this door! --It doesn't matter who I fall in love with, does it?
--About Yui... --You will not find happiness!
"Episode Ten" "The Time Remaining"
Episode Ten, "The Time Remaining."