Sōbu High School
Beneath the shade of the trees at the edge of the courtyard, a woman in a sleek black dress lazily crossed her long legs, watching the opening ceremony with an air of detachment.
She was none other than Hell's Blizzard—Fubuki, Rank #1 among B-Class heroes in the Hero Association.
Behind her, members of the Blizzard Group chuckled under their breath.
"Lady Fubuki, these school assignments are the best, aren't they? All we have to do is sit here and chat and we still get paid!"
"Shame jobs like this only come around a few times a year. If only students had opening ceremonies every day!"
For professional heroes, missions that let them rake in easy money without danger were a rare luxury.
But before their banter could continue, the sharp wail of a spatial quake alarm cut through the air.
Fubuki's face instantly shifted, her calm mask cracking. She shot a sharp glare at the underling behind her.
"Shut your mouth."
"Help the school evacuate the students. We still have a little time—"
Her words froze.
The black dot swelling in the sky was expanding far faster than she had anticipated.
"Impossible… that fast?!"
Her emerald-green eyes narrowed, her beautiful face twisting with alarm.
Before her, in the wide courtyard, nearly ten thousand teachers and students stood gathered.
If this spatial quake detonated, all of them would be pulverized into dust.
Can I stop it?
The question echoed in her heart. Her mind involuntarily conjured the image of her elder sister—Tatsumaki.
The vibrations of the forming quake were already rattling through her senses.
There was no time to hesitate. She had no choice but to throw everything she had at it.
Her graceful body rose into the air, faint light radiating from her form.
The veins on her neck and brow stood out as she clenched her teeth, glaring at the swelling black dot. Her psychic power flared to its limit.
She tried to construct a barrier to contain the quake.
But she had underestimated the sheer impact of its energy.
Her shield screamed under the pressure, fracturing in seconds.
And then—with a sharp crack—it shattered.
Fubuki's face went pale as she staggered midair.
"No… I can't hold it back…"
Even with her strength, she couldn't buy more than a few heartbeats.
Despair prickled in her chest—until she noticed it.
A blot of blackness suddenly bloomed in the sky.
"…What is that?"
Her eyes widened.
That abyssal darkness radiated danger far beyond the quake itself.
And then, before her horrified gaze, it spread wide—like a flower of pitch-black petals unfurling.
It swallowed the spatial quake whole.
"The quake… was devoured?!"
Fubuki's beautiful eyes trembled in disbelief.
At the same moment—
Tōsaka Rin lifted her head, staring at the empty sky, her exquisite face filled with shock and doubt.
"That just now… was that Imaginary Space?"
Even having witnessed it with her own eyes, Rin could scarcely believe it. Could that really have been the legendary conceptual magic, the Imaginary Number Space, swallowing the quake?
Still—
In the chaos, she had felt it clearly: the ripple of magical energy.
There was no mistake. Somewhere nearby, a mysterious magus was hiding.
"Who…?"
Her sharp eyes swept the crowd, searching.
The quake had vanished, but the faculty remained on edge.
Who knew if another would erupt?
Teachers rushed to herd students into the underground shelters.
As the frightened lines slowly grew more orderly, tension finally eased a fraction.
The air inside the shelter was thick and stifling.
Even here, Hiratsuka Shizuka showed what it meant to be a true teacher, directing the student council to distribute bottled water stored within.
Kuzeha's eyes fell on a familiar sight: silver-haired Eri, the half-Russian girl, handing bottles to students one by one.
"Anyone injured during the chaos?"
"If you're hurt, head to the infirmary at the entrance immediately!"
The familiar voice made Kuzeha turn.
There, the long-haired black-haired girl—whose features bore more than a passing resemblance to his own—was speaking while scanning the crowd, her gaze restless as if searching for someone.
And then her eyes found his.
The worry in her expression instantly melted into relief.
"Kuzeha, are you hurt?"
She hurried over, taking his hand.
"…Yuki, I'm fine."
Kuzeha sighed helplessly.
From the corner of his eye, he caught Eri's expression freeze when she saw the girl's bold gesture.
"You call this fine? You're bleeding!"
Kuzeha looked down—only to see Suō Yuki squeezing ketchup directly onto his palm.
"We need to get you to the infirmary, quickly!"
Her sly gaze left him no room to argue. With a wry smile, he allowed her to tug him along.
Suō Yuki—his true younger sister in this world.
Back when their parents divorced, Kuzeha had gone with their father, while Yuki had remained with the Suō family.
"…Yuki, what is it?"
Before he could say more, she suddenly flung her arms around him, burying her face against his chest.
"Brother… thank goodness you're safe."
Her muffled voice trembled with long-held fear and relief.
Kuzeha's eyes softened.
But the very next moment, Yuki pulled back, pouting up at him.
"Brother, why are you spacing out? Isn't this where you're supposed to give me a headpat?"
Her sudden shift left Kuzeha at a loss.
He glanced at his palm—still sticky with the ketchup she had smeared.
"…I've got blood all over my hand."
Yuki gave a little hum, her eyes glinting mischievously.
"Then I'll heal it for you."
Before he could react, she rose on tiptoe.
The next instant, he felt the unmistakable sensation of her tongue slowly lapping at the ketchup in his palm.