Far away from Kuoh Town, several hundred kilometers to the south, lay a secluded coastline—
a stretch of golden sand shimmering beneath the sunlight.
From afar, the horizon blurred into a seamless gradient of azure, where sky and sea fused into one.
It was difficult to tell where heaven ended and ocean began.
On a hill overlooking the coast stood a luxurious villa, newly constructed, its exterior pristine and elegant.
A narrow footpath trailed down from the villa toward the shoreline, disappearing into the dunes.
Dense forests surrounded the entire region, mountains upon mountains of untouched greenery.
Unless one bravely hacked through unmarked wilderness, reaching this place from the outside was practically impossible.
Which was precisely why this paradise remained silent, undisturbed by civilization.
Were it not so inconvenient to access, the breathtaking scenery would already have been developed by human companies, turned into yet another beach resort crawling with tourists.
But it wasn't.
And to certain devils, that made it perfect.
A massive magic circle flared open in front of the villa.
In a burst of light, Izumi and the others stepped onto the golden sands.
Rias Gremory placed her hands on her hips with smug satisfaction, looking up at the grand villa she'd worked so hard to secure.
"Well? Impressed?" she asked proudly.
"I put a lot of effort into finding this place."
"Not bad, right?"
For the sake of preparing the optimal training ground, she had searched relentlessly, combing through territories and records.
Eventually, she struck gold—
a private, pristine beach owned by Sona's family, deep within their domain.
The villa itself had been constructed only recently, commissioned specifically for this project.
Rias could hardly hide her pride.
Originally, she had considered bringing Izumi back to the Underworld—
but the moment she pictured that purple sky, she tossed the idea in the trash.
No way she was holding training camp under fluorescent grape-colored skies.
Better to build something new in the human world.
Even if it took enormous effort.
Thankfully, she and Sona Sitri were close enough that the latter gave her permission.
Otherwise?
Even as heiress of the Gremory family, there was no way Rias would have been allowed to occupy such a gorgeous location.
Izumi surveyed the view—blue beyond blue, sand soft under his feet, air rich with salt and sun.
A slow grin spread across his face.
"This is amazing."
"Training and relaxation, all in one spot."
His boots sank slightly into the warm sand.
"And no strangers to bother us? Perfect."
Seeing him satisfied, Rias finally let out the breath she'd been holding.
Good.
Her efforts had not been in vain.
Everyone headed straight into the villa, which was already fully furnished.
Beds made, kitchens stocked, bathrooms sparkling—
they only needed to drop their luggage and choose rooms.
Which, of course, triggered an immediate stampede.
Doors slammed open, footsteps thundered upstairs, and battle cries echoed down the hall.
Room selection quickly devolved into war.
Once territories were claimed, peace resumed.
And Izumi?
He had already changed into swimwear and sprinted out the front door.
Because if you go to the beach and don't swim immediately—
Are you even alive?
Moments later, the girls emerged as well, each dressed in colorful swimsuits.
The most excited of them was Avrora—the pint-sized vampire known as the Fourth Progenitor.
Despite glaring hatefully at the blazing sun like it had personally wronged her,
the sight of the ocean overrode her complaints.
She changed into a cute swimsuit, bounced down the stairs, and pounced directly onto Izumi's back.
"Hehehe!"
"Quick, quick, take me swimming!"
Her eyes sparkled at the vast, glittering ocean.
Izumi stared at her in disbelief.
A vampire… excited for the beach?
This had to violate some kind of cosmic law.
Without hesitation, he grabbed her by the waist—
And threw her.
"Off you go."
"Catch some fish or something."
"Waaaah—!"
Splash.
Avrora hit the water like a rock.
And…
immediately sank.
Bubbles rose.
Then silence.
Izumi paused.
…Wait.
Does that idiot not know how to swim?
And more importantly—
Can a vampire drown?
Interesting research topic.
He stood on the shore, arms crossed, watching the ripples.
Not rescuing her.
Yet.
The others came racing out of the villa just in time to witness Avrora vanishing beneath the surface.
Asia paled.
"I-Izumi-sama! Did you just kill Avrora?!"
She dashed toward the water, frantic.
Izumi caught her by the shoulder.
"Asia, are you trying to die too?"
He waved lazily toward the sea.
"Relax."
"If Avrora could die from drowning, the title 'Fourth Progenitor' would be a global joke."
"She's S-plus class. If she dies to sea water, people will laugh themselves into hospitals."
At that, everyone hesitated.
Maybe he had a point…
Just as Asia bit her lip in worry—
A surge of freezing magic erupted from beneath the waves.
Crack crack crack—
Ice spread violently across the surface, frost exploding outward in all directions.
And from beneath the ice, a colossal chimera emerged—
a beast of blue crystal, half-mermaid, half-avian, its wings frozen in elegant arcs.
Avrora's 12th Familiar — the Frost Siren.
The entire sea flash-froze in seconds.
Then Avrora crawled up from under the ice, sputtering seawater, face twisted in disgust.
"Bleh. So gross."
She glared murderously at Izumi.
Izumi ignored her.
He patted Asia's shoulder, cheerful.
"See?"
"Perfectly fine."
"Avrora's still alive and stupid."
The girls collectively stared at him.
Avrora stomped across the frozen sea, leaving a trail of ice in her wake.
Her swimsuit fluttered, her tiny arms pumping furiously.
"You evil human!"
"You are literally a devil!"
She reached the shore, leapt—
And bit Izumi.
With all her strength.
Her baby fangs struck his skin…
And failed to penetrate.
A tiny clink echoed.
Avrora froze.
Her eyes watered.
She clutched her jaw.
"Ow ow ow—!"
"That hurt!"
Her lips trembled, tears welling up.
In that instant, every girl present experienced a surge of maternal instinct.
They swarmed her, scooping her up, hugging, squeezing, patting—
Avrora squeaked helplessly, trapped in a pile of affectionate torture.
This was the fate of the fearsome Fourth Progenitor.
A cursed mascot.
Whenever she tried to resist—
Himejima Akeno silently produced an ice cream.
Instantly breaking her will.
Izumi covered his face.
So much shame.
The title "Progenitor" had never been so tragic.
Eventually, Izumi clapped his hands.
"Alright, enough harassment."
"Let's get serious and discuss our training plan."
The girls loosened their grips, turning toward him with anticipation.
Even Avrora stopped struggling—
mostly because she couldn't escape anyway.
A quiet breeze washed over the frozen shoreline.
The fun was over.
Training was about to begin.