Chapter 46: Memory Echoes

"But really, it’s been such a long time, Sensei! Was it since that time, maybe?"

Projected on the hologram, as energetic as ever, was Kashiwa Mayumi, Head of the Supplementary Lessons Department at Millennium Science School.

"Yeah. You helped out the Game Development Club back then—thank you for that."

"It’s fine, really. We only did it because we wanted to... Oh, wait, didn’t we have this conversation already?"

The Game Development Club—a club at Millennium Science School with members Hanaoka Yuzu, Saiba Momoi, Saiba Midori, and the newly joined Tendou Alice.
As the name suggested, their activities revolved around developing games... or at least, that was the idea. In reality, the club was barely functioning.

With too few members and no notable achievements, their one completed project, Tales Saga Chronicles, had even been crowned the proud winner of this year’s Worst Game Rankings.

Naturally, a club like that couldn’t expect much budget support and was even facing disbandment—until Mayumi’s Supplementary Lessons Department stepped in to help them.

"Actually, some of our members even ended up assisting C&C, so the balance sheet’s probably deep in the red… sorry about that."

"Not at all. You really helped us out."

Mayumi let out a small sigh and slumped her shoulders apologetically toward Sensei.

"Wait, hold on. What do you mean by that?"

"Uh... r-right, about that, Sensei—the reason I reached out so abruptly this time is…"

"Hey, don’t look away from me. You can’t just gloss over that."

With Asiri’s sharp gaze drilling into her, Mayumi tried to continue the conversation—but Asiri clearly wasn’t going to let it slide.

"How does a situation like that even happen? What about communication within your department? I tell you all the time to share information properly, don’t I?"

"Ugh—enough already, you’re so noisy!"

Caught off guard by Asiri’s rare burst of anger, Mayumi reflexively snapped back.

"Wha—w-wait, did you just snap at me!?"

"I can’t help it! We had our hands full back then, okay!? It was really rough!"

"You’re mad at me like I’m the bad guy here!"

From Asiri’s perspective, the outburst seemed absurd—but from Mayumi’s, being scolded one-sidedly didn’t feel fair either.

At the time, Mayumi and the Supplementary Lessons Department had been slow to learn that Sensei had arrived at Millennium. They ran every possible simulation to figure out how to approach him and recruit him as an ally as soon as possible.

And yet, in the end, they only got involved by chance—through the Game Development Club’s request for help. Their efforts hadn’t gone to waste, but it was hard not to feel frustrated.
There was even a brief period when she seriously considered using a honey trap, thanks to some unfortunate rumors.

Of course, her members helped where they could, but they all had their own duties. In short, both Mayumi and her team were completely overwhelmed.

"What do you mean by ‘hands full’!?"

"T-that’s...!"

"...?"

When she glanced at Sensei, he simply tilted his head in confusion.

Unable to say something like that in front of him, Mayumi gave up on explaining further.

"…Fine, fine. My bad, okay? We’ve already taken steps to make sure it won’t happen again."

"I see... yeah, sorry. I went too far too. My bad."

She’s really scary when she gets angry… Mayumi grumbled inwardly, then turned back toward Sensei.

"You two seem pretty close, even though you’re from different schools."

"...I guess so."

Mayumi almost wanted to ask what part of that argument looked like friendship, but decided to let it go.
After all, there’s that saying—“the closer you are, the more you fight.”

"And that’s actually related to what I wanted to talk about today."

"Hehe... we’re best friends..."

There wasn’t any urgent reason to rush, but neither was there a reason to dawdle.
Wanting to move things along, Mayumi shifted gears toward the main topic.

Meanwhile, Asiri was grinning dopily at the word “best friends,” not thinking too deeply about it. She already knew she and Mayumi got along well—but hearing it said aloud still made her happy.

"Anyway, let’s get to the main topic."

Ignoring Asiri’s expression, Mayumi pulled up a series of files and began speaking.

"Right. I asked you to let me know if you heard anything about Arius Branch, didn’t I?"

"Yeah, you did... Sorry, I still haven’t been able to dig up much yet."

"That’s fine. I didn’t expect results that quickly anyway. So, about this Arius Branch..."

"Hmm, where should I start..." Mayumi spun idly in her floating chair, rising a little higher with each turn.

"Maybe start with how Trinity was formed?"

"That’s it!"

She stopped abruptly about four or five meters in the air, then quickly descended back to the ground.

"That’s more your specialty, isn’t it, Asiri? You’re enrolled at Trinity, after all."

"R-right... It’s a bit complicated, but I’ll do my best."

"Thanks. I appreciate it."

"O-of course!"

She was glad she’d reviewed her notes the night before, before visiting Sensei at the Supplementary Lessons Department’s annex for their camp.

With a small sigh of relief, she pulled out her memo pad.

"Flash sale, tomorrow at five... ah—wait, that’s the wrong note."

"…"

"S-sorry..."

Under Mayumi’s cold stare, Asiri blushed and cleared her throat awkwardly.

"O-okay, um... So, first off, Trinity General Academy—as the name suggests, it’s a collective made up of several different schools."

"I’ve heard a little about that. It’s organized around three main branches, right?"

"Y-yes, that’s right... um, so we can skip this part..."

She flipped to the next page, eyes scanning for where she’d left off.

"R-right, the three main branches. Those are what make up the current Tea Party... I think you might’ve heard that from one of them directly..."

"Yeah. That’s why there are three student council presidents, right?"

"Y-yes... there’s Kirifuji Nagisa, Misono Mika, and..."

For a moment, Asiri hesitated, a particular memory flashing through her mind.
But realizing it wasn’t the time to waver, she shook it off and continued.

"Yurizono Seia, who’s currently hospitalized. Those three make up the Tea Party... B-but anyway, that’s all about them for now—uh—"

"Relax, take a deep breath... I’ll take it from here."

Seeing Asiri slowly start to breathe normally again, Mayumi picked up where she left off.

"Yeah, pleased to meet you."

『Indeed. Though honestly, this part is something she knows better than I do… oh well. Sensei, that’s where your explanation about the founding of Trinity General Academy ended, wasn’t it?』

"…? Yeah, that’s about it."

『…I thought so.』

Letting out a small sigh, she muttered as if to herself, well, of course.

『…Sensei, I have one question. Do you really believe that all the schools have joined hands and truly come to understand one another? Even though, until recently, they were at each other’s throats.』

"…"

『I know it’s not the best timing to bring this up, with the signing ceremony for the Eden Treaty right around the corner… but judging from your reaction, you’ve already realized it. That’s right—there were schools that opposed reconciliation and were left behind. And that very place is—』

"Th-that’s the school we’re looking for—Arius Branch School…!"

Recovering from her deep breaths, Asiri jumped back into the conversation, picking up right where Mayumi had left off.

『Exactly. But, Sensei… you’ve never heard of Arius Branch School before, have you? Not that it’s just you—most people living in Kivotos don’t even know it exists. You understand what that means, don’t you?』

"…!"

『That expression… I see. But it can’t be helped, really. At least, not for the people they were back then…』

Mayumi spoke softly to Sensei, whose face had grown heavy with sorrow.

"B-but Arius Branch School wasn’t completely wiped out…! They were persecuted, yes, but they didn’t vanish completely…!"

『That’s right. Arius Branch still exists—somewhere in Kivotos. In their own autonomous district… quietly, in hiding.』

"…I see."

『Yes…』

But then, as if gathering herself again, she continued.

『Now then—this is where the real story begins.』

"The real story…?"

『Yes. We’ll have to go back about ten years.』

Mayumi closed her eyes slowly, as though reminiscing about that time ten years ago.

When she closed her eyes, she could always see it—the state Arius Branch was in back then.

She had been taken in and raised by extremists.

That was why she was made to believe she lived only to enter Arius Branch and exact revenge on Trinity. That this was her only path forward.

If she did that, she wouldn’t be hit. She wouldn’t be scolded.

She’d be loved. She’d be respected.

『…You’re allowed to choose the place that matches the future you want for yourself.』

So when someone told her that, Mayumi hadn’t known how to respond.

What she wanted to do? The future she wanted to choose? Being asked that now—it meant nothing to her.
After all, it was the first time anyone had ever respected her will.

But eventually, she ran away from that place.

She felt that if she stayed, she’d never understand what those words truly meant.
She wanted to see what lay beyond—to go somewhere else entirely.

And then… ah, what was it again? She came back to herself.

Right, she had been talking about something from ten years ago.

『My apologies, I got carried away collecting my thoughts. So, ten years ago—there was an uprising at Arius Branch School.』

"An uprising…?"

『Yes, an uprising. Simply put, it was a battle between those obsessed with revenge against Trinity and those who no longer cared.』

When put into words, it didn’t sound like much of a story.

But in truth…

"B-but… I-I think there were… casualties… people who died, or—or maybe…"

『Asiri.』

Mayumi’s sharp tone cut her off, calling her name.

『It’s fine. I’ll explain.』

"…Thank you, Mayumi-chan…"

『…』

Unlike herself, Asiri had lost someone dear to her.
Not by blood, but still a sister.
Mayumi could easily imagine the weight that pain carried.

『…About your sister. Is it alright if I talk about her?』

"…Yeah."

『…Phew… thank you. Get some rest for now.』

She stepped closer to the teacher’s holographic image, lifting her gaze toward his higher position.

『…That uprising ten years ago… I believe there were casualties. In the literal sense—some had their Halos destroyed.』

"…!? That can’t be…!"

『Hard to believe, isn’t it? For us, death is an uncertain concept… but apparently, there are ways to destroy a Halo. And Asiri’s sister… she’s been missing ever since that uprising ten years ago.』

"…"

Faced with such a cruel truth, Sensei was left speechless.

This was the first time he had ever encountered something like this in Kivotos—someone’s Halo being destroyed.

The Halo was deeply connected to a student’s consciousness and spirit.
Its destruction—its collapse—could mean only one thing: unmistakable death.

『…Now you understand, don’t you? Why we know about the uprising ten years ago. Why Asiri’s sister was at Arius Branch School.』

"…So that means, Mayumi and Asiri—"

『Yes. We’re both former Arius students. Although, to be precise, we weren’t from the Branch School itself but from the elementary and middle schools within the Arius district.』

"I see… that’s why…"

『That’s right. Asiri and I are close. And there are many other former Arius students enrolled in various schools now. Some are still connected to us. As for what we’re doing—and why—I’ll explain that once this conversation is finished.』

"…I’m sorry. For making you recall something painful."

Sensei clenched his fists, struggling to contain a storm of emotions as he quietly apologized.
No one would want to remember something like that under normal circumstances.

『What are you apologizing for? I was the one who started talking.』

"…"

『Well, I don’t mind, but… please, keep an eye on her. She must’ve left plenty of happy memories back there, too.』

"Count on me."

『Good. I’m trusting you.』

───Ah… I really was right to trust Sensei.

Mayumi reaffirmed that thought.
Even though her actions back then had earned her plenty of criticism, the very fact that she could speak about it like this now felt like a blessing.

As she recalled the smug faces from Gehenna who mocked her decision back then, she made a mental note—next time we talk, I’ll make them regret their sarcasm.
With that, she turned her focus back to the matter at hand.

『The result of the uprising was the victory of the revenge faction. Which means that Arius Branch School now… still seeks revenge against Trinity.』

"Th-that’s…"

『Hold it. Everything has an order to it, you know? …Are you feeling better now?』

"Y-yeah… thank you…"

Relieved to see Asiri returning to her usual self, Mayumi continued.

『And then, about a year ago—an incident took place.』

"An incident…?"

『Yes. The Trinity General Academy Attack. A small, elite strike force assaulted Trinity, causing massive damage. Fortunately, very few regular students were harmed.』

Thinking back on it now, something about that still felt deliberate.
Sure, one could argue the attackers were too undermanned to target the general student body… but still.

『And most likely, during that attack, Yurizono Seia was seriously injured—and is still hospitalized.』

"B-but that’s not—"

『Almost certain.』

Asiri tried to protest, but Mayumi cut her off.

『And the ones who carried out that attack were…』

"…Arius Branch School. That’s what they’re saying…"

"…I see."

『Yes. Arius still bears hatred toward Trinity. They’re quietly waiting—watching for their chance to strike again.』

Mayumi lowered her gaze, eyes closed in thought.

Then she slowly lifted her head.

『───At least, that’s what I believed. Until recently.』

"…What?"

『The situation has changed.』

Taking a slow breath, Mayumi steadied her mind.

What she was about to reveal might earn her anger—or worse.
But she couldn’t avoid it any longer.

『…Before I continue, I owe you an apology, Sensei. In this case, I resorted to a method that was cowardly and—frankly—lacked any sense of consideration or ethics. But I couldn’t reach a decision otherwise. That’s why I came here today.』

"W-we… both did…!"

『…』

"Wh-what do you mean…?"

Before Sensei could finish his question, Mayumi met his eyes directly—her expression firm with resolve.

『…Trinity’s traitor—Shirasu Azusa—is probably a student of Arius Branch School.』

"…!?"

The words she spoke marked a turning point—not only for Mayumi and Azusa, but also for her, the one who wasn’t there with them now.