The Day It Was Born

Over a decade had passed since a [Hero] summoned from another world defeated the [Demon King].

Once the [Hero] returned to his own world, the monsters spawned by the [Demon King] dwindled drastically in number.

The monsters that had once overrun the world were now confined to the depths of forests and caves.

And the few that remained were thinned even further by present-day adventurers and knights.

—A world ruled by humans and demi-humans.

A world where monsters did not exist.

A world of peace.

A world where people quarreled with one another.

A world where humans and demi-humans worked together.

A world where there was no [Demon King].

A world where there was no [Hero].

A world governed by the three rulers who had traveled alongside the hero.

That was this world.

[A World Saved by a Hero From Another World] — Euswara.

A garden world, said to have been created by Goddess Euswara.

A world of swords and magic, where spirits, demi-humans, demons, and humans lived together.

A world where, in the not-so-distant future, monsters would perish.

—Or so it should have been.

That was what everyone thought.

Humans, spirits, demi-humans, demons, the goddess — even the [Hero], all of them believed it.

After all, wasn't that simply how things had to be?

Monsters had been spawned by the [Demon King], who no longer existed.

So surely there was no way for any more to be born…

 

*

 

One of the three rulers: the Magic Queen [Leticia].

Leticia governed the northern country of [Fonteau].

Having traveled at the hero's side, Leticia the mage had played her part in striking down the demon king.

Even her own allies had marveled at her. With her fearsome mana she had subjugated the demon king, her genius elevated to the level of a natural calamity.

Her mana was tremendous, and although it didn't reach the likes of the demon king or the hero, it was extraordinary even compared to the elves who were so skilled in magic.

Both Leticia herself and those around her believed as much.

The passage of time had let the demon king's terror fade from her memory, but it had also refined her beauty further still.

Even in those days she could certainly have been called a beauty.

Flowing silver hair, long and lustrous as silk. Large red eyes set beneath neatly shaped brows. Her gaze was sharp, but even that was simply another one of her charms.

Her ears were slightly pointed, likely thanks to the elven blood mixed in her lineage.

They weren't as prominent as a full elf's, but neither were they as rounded as a human's.

It was the part of herself that Leticia loathed — and the part that the hero had loved.

A human who was also an elf. An elf who was also a human.

That was Leticia.

Leticia Fonteau. The Magic Queen, the mage who had slain the demon king. She had borne the hero two children.

Even so, her body had not deteriorated from childbirth in the slightest. If anything, she had taken on a [Motherly] luster.

Leticia was unusual among elves in that she favored white clothes.

Elves were called the people of the forest, and most of them preferred bright green attire, yet Leticia wore a white dress.

Though the dress was luxuriously adorned, the cloth itself was thin and revealing, doing little to conceal the queen's figure.

Her shoulders were bare, the swell of her rich breasts peeking out at the top. Even so, the pure white dress did cover her from chest to ankles.

But with her slender arms, her rich breasts, a waist so narrow it seemed it might break if anyone embraced her too tightly, and a soft rear that swayed gently with each step, her charm and figure stood out all the more beneath that tight-fitting attire.

Even the way she concealed herself felt seductive.

There was no shortage of men who entertained lewd thoughts at the sight of her.

Even the [Hero] had been one of them.

Even the hero she had traveled with in her youth had desired his companions many times over — both Leticia the mage and Frey the hunter.

It was in those days that she had first realized her own beauty. That was when she first unconsciously began to use it as a weapon.

Nowadays, she wielded it deliberately.

Whenever she walked down the hall, the men's gazes would drift toward her ample, faintly swaying chest. Even through the protection of dress and undergarment, their abundance and softness were plain at a glance.

It tempted the male soldiers. A dizzying feast for the eyes. Her beauty, her body, and the icy air about her that kept the other nobles at a distance.

Every part of her was beautiful.

An absolutely beautiful queen.

That was Leticia.

"Good morning, mother."

The one greeting her was her elder daughter in an azure dress, [Meltia].

With silvery hair inherited from her mother and an adorable look on her face, she stood about a head shorter than other girls her age.

And yet — her chest. The part that might be called the very symbol of womanhood.

It was by no means a matter of being plump. From her lovely face to her dainty shoulders, down to that bountiful chest and a waist that could be cinched tight in a corset without the slightest discomfort.

That was Meltia.

"Good morning, Mel. Do you have studies after this today as well?"

"Yes, mother. I'll be getting breakfast, then going to school."

"Is that so? Work hard."

"Yes."

That was the extent of their exchange. Mother and daughter only ever spoke in passing like this. Meltia bowed slightly and stepped aside to make way.

Being royalty was troublesome. Back when she had traveled with the hero, Leticia had known nothing but happiness. She lost herself in the recollection.

There had been no nobles, no royalty, nothing of the sort — they could speak to each other as friends. No formal speech, no need to put on airs. They were happy, dazzling, beautiful memories.

She thought it might do her daughter some good to experience something like those days.

She understood perfectly well why it couldn't be helped, but being royalty was still such a bother… as she walked along thinking about such things, she eventually arrived at a door.

She knocked lightly, but there was no answer.

Unbothered, she went to open the door anyway, only to find it locked, the knob refusing to turn. Even so, she seemed to have expected as much and showed no surprise whatsoever; her glossy lips quietly wove a spell.

Unlocking magic.

There was such a thing as privacy, even within a family, but she opened the door without a second thought and stepped into the room.

A conspicuously large canopied bed dominated the room — a luxurious piece of furniture that all but shouted "royalty."

Leticia's family preferred simple rooms themselves, but appearances mattered for the royal family. Even when it came to a private chamber that other nobles were unlikely to ever see.

There was a figure still lying on the canopied bed despite the sun already being high in the sky. Leticia approached and let out a sigh.

"Maria."

In truth, this was a task for the chamberlain rather than the queen, but on this point Leticia wouldn't yield.

Waking her children was a mother's duty.

Gently shaking the lump on the bed, she called out the name several times. After a little while of that, black hair came crawling out from beneath the covers.

The exact opposite of Leticia and Meltia's silvery hair. The darkness of night. A deep, deep black — the very same shade as the hero's.

Her beloved daughter, the one who had inherited the hero's blood: [Mariabelle].

She had glossy black hair and matching eyes. Yet her skin, inherited from Leticia, was so fine-textured that it made for a stunning contrast against her hair.

It might be called frugal and admirable to live modestly, but she was scarcely dressed up at all, wearing plain pajamas wholly unbefitting royalty.

Leticia felt her daughter took after her father the hero in many ways. He, too, had never bothered acquiring anything beyond the bare essentials.

The nobles didn't think much of it, but Leticia loved even that part of Mariabelle.

Whenever she looked at her child, she could remember the hero who was no longer with her. That was something she truly cherished.

"Wake up. You'll be late for school, you know?"

"… Mou, is it that late already?"

"Really now… just like your father, hopeless in the mornings."

"Muu…"

At Leticia's small laugh, Mariabelle's cheeks puffed out slightly.

She didn't like being compared to her father. Even so, Leticia thought her adorable little pout was perfectly suited to her age.

But it really couldn't be helped. With that thought, she stroked her daughter's head, combing through her soft hair.

"Fufu, you have beautiful hair."

"But everyone at school says it's disgusting."

"Is that so?"

Black hair was rare in this world.

In fact, aside from Mariabelle, who was tied to the hero by blood, there wasn't another person in the entire country who had it.

And so it was treated as a curiosity, something to be feared, something strange.

It was unbearably sad that the hero's color was regarded as heresy in this world.

"Even so, one day you'll meet someone who loves this hair."

"… I wish."

At Mariabelle's mutter — which sounded as though she'd given up somewhere along the way — Leticia's chest tightened.

She loved her so dearly, and yet her child was beginning to hate the world.

But it couldn't be helped. No magic existed in this world that could change a person's hair or eye color.

So Leticia kept caressing that jet-black hair. She did it so her daughter would understand, beyond any doubt, that she was loved.

For her part, Mariabelle gave herself over completely to that motherly affection, letting her hair be combed smooth by her mother's hand. These were the only times she truly cherished.

Such peaceful moments.

The demon king had been defeated by the hero, and from now on these peaceful mornings would surely continue for all eternity.

Such happy scenes would surely go on.

 

*

 

The magic kingdom of [Fonteau].

At its northernmost tip lay a cave where, over a decade ago, the magical silver known as [Mithril] had been mined.

That magical silver had since been exhausted, so the place was now nothing but an empty cave, and no one went near it anymore.

It was stagnant and gloomy, sunlight unable to reach its depths. A place where the [Grudges] of those caught in sudden cave-ins and the like had quietly piled up.

Even so, it wasn't silent. Water dripped now and then from the ceiling, and the screeches of roosting bats echoed off the walls.

Bats stirring overhead, water tapping against stone, and enough insects on the ground to send any woman or child shrieking the other way.

It was that sort of repulsive, filthy, foul, polluted, stagnant place.

In its own way, though, it was peaceful. Bats flew about, disgusting insects crawled across the ground, and vengeful ghosts sang their despair.

It had continued like this even after the mithril ran out, and it should have gone on continuing far into the future.

But that came to an end.

At this very moment, on this very day, that peace ended.

Gii.

With a sound lower in pitch than any of its usual cries, a bat tumbled to the ground. At the base of its neck clung a single insect, no larger than a thumb.

From the insect's mouth protruded a needle slick with paralytic poison, and now it was settling in to feed on its paralyzed prey. Over the course of several days it had crept up the wall, inching along bit by bit so the bats wouldn't notice, and at last it had felled one with that poison.

Finally, it had caught its prey.

The insect had no feelings as such, but even so it let out a faint sound of pleasure.

This was the natural law of things. As it had been for all time up to this moment, and as it would be for all time to come.

—However, who could have ever expected that very principle to give birth to the worst possible outcome?

The insect extended a slender tendril from its mouth and began to feed on the fallen bat.

It would exude acid from that tendril, dissolving its prey bit by bit as it fed.

Its meal wasn't a large one. Dissolving the skin at the nape of the bat's neck, it consumed only a small amount of the soft flesh underneath.

And with that, its meal was over.

The rest of the carcass would be left to the insects that couldn't climb the rock walls or take down bats themselves.

In the end, nothing would remain. They would devour even the bones.

In fact, the insects were just beginning to swarm the bat's corpse when — zuzu, a sound arose, as though something were just barely dragging itself along the cave floor. It was a tiny sound, well beneath the threshold of human hearing.

That sound, and the slight vibration with it, sent the insects scattering.

What had appeared in the cave's darkness was a [Distortion]. A newborn monster.

Zuzu. A sound that, until this point, had never been heard in the cave.

On closer inspection, it looked like a mass of mucus draped in deep black, like a warp in the cave's very darkness — a dark slime.

Over a decade ago, while the demon king still lived, it would not have been an unusual sight. Its formal name was [Black Ooze].

A mid-tier monster of the slime variety, and a formidable specimen in its own right, provided it lived long enough.

The catch was: only if it lived long enough.

A newborn black ooze was weaker than even a common house dog. It was no larger than a child's fist.

Honestly, it would normally have just rotted away, unable to catch any prey. Most likely it was destined to be eaten by the swarms of insects instead.

But this particular slime had a prize lying right in front of it.

And not just something on its own meager level, either — a substantial prize.

Following its instincts, the slime drew the bat's corpse into its body. Slimes took prey into themselves to digest it little by little, drawing nourishment from it over time.

It was lucky. And that very luck might also be called bad fortune — it was unlucky.

If this had been the lowest-rank, utterly ordinary slime.

No — if it had been any other slime.

Then, without prey, this slime too should have rotted away, its fate unchanged.

But this black ooze had obtained food.

And with that, a change began.

The slime, no larger than a child's fist, swelled in an instant after taking in the bat.

This was the defining trait of a black ooze.

It could convert digested nourishment into added mass on the spot. Now that it had absorbed the bat, the tiny slime was already beyond the insects' power to kill.

—At this point, what could still kill this slime inside the cave were the bats clinging to the ceiling, the lizards deeper in, or the wild dogs near the entrance.

But this slime was also clever. No — perhaps one should say it possessed intelligence.

Instead of setting its sights on big prey, it first set about rooting out the tiny insects nestled in the rocks.

A single insect was small, and the mass it added by preying on one was negligible. Even so, the insects in this cave were as numerous as the stars in the sky.

It hunted and ate insects. Driven by instinct, it ate and ate, ravenously and without rest. And it grew.

After several days had passed, it crawled along the wall and snared a bat.

The living bat fought back, but once it was in the slime's grasp there was no escape. The lizards too tried to bite back with their fangs in desperation, but over the past few days the slime had grown so large that they were now helpless against it.

It hadn't been able to digest the carapace of the insect that had preyed on the earlier bat. And because the insect itself was small, it had offered very little nourishment in any case.

However, the slime had acquired an interesting ability. A paralytic poison strong enough to take down prey larger than itself was now mixed into the slime's fluid.

Thanks to that, hunting grew easier. After the bats, lizards, and insects inside the cave had all been picked clean by the slime, it extended a tendril outside toward a wild dog lingering near the entrance.

It already understood that its fluid was poisonous. The wild dog, wary at first, took a small bite — and promptly fell into convulsions.

Once it had finished off the wild dogs in the vicinity, the slime returned to the cave. It knew nothing of homing instinct, but as far as the slime was concerned, this place was home.

By now, the only company the slime had in this cave were the grudges that dwelled there. That was all.

Where an ordinary cave might have been still and calm, this one had become a cave of death, filled with the dirge of vengeful ghosts.

By this point, the slime had grown to the size of a cow.

Over a decade ago, in the era when the hero and the demon king fought, a slime of that size could occasionally be seen.

But now, with monsters no longer appearing, the likes of a black ooze could only be found in illustrations.

Everyone believed in their peace, believed it would last for all eternity. The age of the demon king had been too long, and they could no longer let go of the happiness they had finally obtained.

That was simply how it was.

Right now, no one realized that a monster had been born.

After that, a month's time slipped by.

By the time there were no wild dogs left outside for it to prey on, the residents of the nearby village had begun to wonder what was going on.

The place had prospered as a mining town in days gone by, but once it became impossible to dig up any more magical silver, the city had shrunk from a town to a mere village.

These days, only a dozen or so people lived there. It was a country village that scraped by on dairy farming.

There had been wild dogs attacking the village's cattle for some time, leaving the elderly residents at their wits' end — but recently, the dogs had stopped showing up.

It was strange. There was food in the mountains, but not enough to keep a pack of wild dogs satisfied.

Once they had tasted cattle, the dogs had kept coming back to attack the herd no matter what. Snare traps had killed quite a few of them, but never enough to truly protect the cattle.

There had simply been too many wild dogs.

And yet now, none of them had shown up at all.

Had they given up?

Someone floated the idea, but it was dismissed at once. Wild beasts didn't entertain such noble thoughts.

Still, it was a fact that they had stopped coming. It was a mystery, but the villagers decided to chalk it up as one of Goddess Euswara's miracles and offered her their prayers.

They were the sort of country village where that sort of thinking came naturally. Even so, in such a country village, there was one spirited old man.

Taking up his weapons and donning his old gear, he set off toward the mountain. His aim was to find out what had happened to the wild dogs. The other villagers tried to stop him, but the old man wouldn't listen.

This old man believed himself to be strong. In his youth he had killed countless monsters. Slimes and goblins aside, he had even taken on and brought down creatures many times his size — ogres and the like — alongside his comrades.

Old age might have caught up with him, but his strength had never dulled — or so he believed.

He set out up the mountain. Soon out of breath, he sat down on a rock to rest. Climbing a mountain was hard on an aged body.

He gulped down water as if he were bathing in it, then drew a deep breath. He had already climbed a surprising way up the mountain. Beyond this point lay only the mithril tunnel.

And yet he still hadn't run into the wild dogs. Come to think of it, he hadn't seen any wild rabbits either.

What was going on?

His instincts were telling him that something was wrong.

Age might wear a man down, but his intuition only sharpened. His body, however, had grown old and tired.

—By the time he noticed, his body could no longer move.

Paralysis. His aged body had failed to register the slight stimulus as the paralytic poison seeped into him.

The effect was instantaneous. Paralytic poison from a slime the size of a cow was far too strong for one old man.

Moving his body was out of the question — even his heart stopped. The old man died without ever understanding what had happened to him.

And so the slime preyed on the old man.

Slowly, ever so slowly.

… And so, the curtain rose on the worst possible scenario.

On this day, the black slime acquired knowledge. Knowledge of how to kill monsters, knowledge of humans, knowledge of life… and sex.

Right now, no one — not even the slime itself — realized it. That this slime was a mutation. That it could steal the unique traits of the things it ate.

Like that insect's poison.

Like human knowledge.

If the first human it had eaten had been a woman —

If that had been the case, it would have stolen the trait of [Pregnancy], and the worst-case scenario would have been averted.

However, the first one it had devoured — old though he was — had been a human male.

And so the slime obtained things. Knowledge of humans, knowledge of life — and knowledge of how to impregnate women.

Humans were sinful creatures.

To say nothing of their own kind, humans would conceive children with all manner of races: elves, sirens, even beastkin.

The world still didn't know.

In this world where there was no demon king left to spawn monsters, a monster had been born.