A World Without Sensei: Sensei's Disappearance
Tachibana Saori first learned of that fact on the eighth day or so after Sensei vanished from Academy City.
Sensei occasionally disappearing for a few days was nothing out of the ordinary. The Integrated Student Guidance Department he belonged to was tasked with mediating all sorts of disputes in Academy City—or preventing them before they even arose. Any student who'd ever received his help, or been on the receiving end of his meddling, knew that well enough. So at first, no one thought much of it.
But once whispers started creeping in like, Isn't this taking a bit too long, even for him? the real crisis began.
The Integrated Student Guidance Department was, at least nominally, a subordinate organization of the Student Council. No matter how busy he got, Sensei always made a point to show up at Student Council events. When he skipped one for the first time ever, word spread like wildfire across the whole of Academy City that Sensei was missing.
And as you'd expect, the first arrows of blame flew straight at the Student Council.
"Our Student Council has been doing everything in our power to locate the missing Sensei, but we have yet to see any concrete results."
"Going forward, the Student Council plans to deploy every available resource to find him..."
"We deeply regret that such an unfortunate incident has occurred in this garden of learning, where all students should feel safe to focus on their studies."
At the emergency press conference held shortly after, the Student Council made their position clear like that. But most students watching the broadcast didn't buy it.
After all, in modern society, it was next to impossible for a single person to vanish without a trace. And Academy City was where superpowers and cutting-edge science fused, with every new technology rolling out first. For someone under the spotlight of every student in such a high-tech hub to just disappear overnight? It was far more natural to assume the Student Council was lying to cover up inconvenient truths.
As distrust in the Student Council snowballed exponentially after the conference, they scrambled to restore their plummeting credibility. But those desperate flailings only cracked the fragile power balance that had kept Academy City stable.
And the one who seized that fractured power structure most aggressively was none other than Tachibana Saori.
As student council president of Übermensch Alliance School—one of Academy City's three prestigious academies—and the city's strongest psychic esper, she wielded her abilities to full effect, seizing control of the chaos-stricken Student Council in a flash.
But contrary to initial suspicions, the Student Council truly knew nothing about Sensei's disappearance. They were incompetent, sure, but innocent. Realizing that, Saori formed a new hypothesis.
Sensei is still inside Academy City.
If someone malicious had kidnapped him and dragged him out of the city, there would've been some trace left behind, no matter how they did it. But the database showed zero records of Sensei's biometric ID leaving city limits.
Which meant the culprit was an inside job.
In a situation where every faction has their eyes peeled wide open, no lone individual could pull off something this bold.
Her first suspects were the two largest factions in Academy City aside from Übermensch Alliance School: Kochou Girls' Academy and Choutenjouki Academy.
If an organization had managed to abduct him without a single trace, they'd top the list.
She organized an inter-academy exchange under the pretext of sharing intel, but contrary to expectations, she gleaned nothing useful. If anything, she learned both schools suspected each other of being behind the kidnapping force.
With the investigation back at square one, a second possibility she'd been ignoring wormed its way into her mind.
What if Sensei hadn't been kidnapped—what if he'd vanished on his own?
...No, that can't be.
A man who cared so deeply for his students, just gone without a word? If so, he'd have tipped off someone trustworthy.
But if not the Student Council, not her, not Kochou Girls' Academy, not Choutenjouki Academy—then who the hell knew where the missing Sensei had gone?
And the thought that he might have someone else he trusted—a student other than her—made her chest ache.
She was the one with no reliable adults in her life except Sensei. The idea that he had a bunch of reliable students besides her? Unbearable.
So she consciously shoved that possibility aside. For Sensei's sake—and her own.
No matter how long it takes, I'll find you. Sensei.
Two years passed, and a staggering amount happened in Academy City.
The Student Council, failing to find Sensei, was forcibly disbanded over the fallout. Tensions boiled over between the two mega-academies that had eyed each other as culprits. Japan's government intervened, and megacorp Cyclops even tried snatching control of the city.
Amid the endless chaos, Tachibana Saori threw every tool at her disposal into the search for Sensei.
But still, no trace. Not inside Academy City. Not outside. Nowhere.
As exhaustion started to set in, one of her subordinates suggested she call it quits. That she'd done enough—that Sensei would understand.
It was a sweet temptation, but she couldn't yield.
Sensei was the one who'd saved her from crumbling away, mistrusting everyone due to her powers' side effects.
So when a window of light popped up mid-work, revealing Sensei's face on the other side, she thought it was a hallucination.
But it wasn't.
His face—still vivid in her memory as if she'd seen it yesterday—stared at her intently, unchanged from two years ago.
Still as pretty as ever, even after all this time.
She rarely showed emotion in front of others, but as his thoughts flowed naturally into her mind—
"Ah... A-ahh...!"
Tears of joy spilled out before she knew it.
It's real. It's really Sensei.
The Sensei she'd strained so hard just to reach was right there, before her eyes.
So she reached out without thinking.
The glowing window might be a trap.
But Sensei—the one she'd yearned for so desperately—was beyond it. No hesitation.
Over those two years, she'd gone from high schooler to college student, become Student Council President overseeing all of Academy City, even taken over the megacorp gunning for control—all just means to find her missing Sensei.
The instant her slender finger touched the light, her office was gone.
She stood in an unfamiliar place.
***
"Wha...?"
Sensei, whom she hadn't seen in two years, gawked up at her with a dumbfounded look.
Then, as if he couldn't believe this was real, he pinched his own thigh.
"Yeowch!"
The goofy action didn't match his serious face at all. Which only made her more certain.
This was the real Sensei—the one she'd searched for so long.
Questions piled up: What had he been doing? Why'd he vanish without a word? Didn't he miss her?
But bombarding him would just overwhelm him.
So she played it cool, glancing around.
"This where you're living now, Sensei? Doesn't look much different from that old school on-duty room. You eating properly?"
She'd tossed it out lightly, just to ease into conversation. But did it hit a nerve? He suddenly averted his eyes.
Suspicion piqued, she turned—and spotted a convenience store lunch box on the computer desk.
"......"
It hurt to see.
No one to cook for him, so he was probably living off ready-meals and frozen junk, wrecking his health like she used to.
The words slipped out unbidden.
"I'll make you some proper food first. We can talk after."
Feed Sensei a real meal—for starters.