Markin (87 years old, an adult male, and long-eared) is the Great King of Eromanga Island!
Originally, Markin was the biggest idiot on the island. He was such an idiot that he wasn't even aware of just how incredibly stupid he was.
But then one day, he suddenly fell ill and suffered for three days and three nights. When it was over, his mind was clear and refreshed. He had shot straight to the position of the island's greatest genius.
The newly intelligent Markin began by taking fierce revenge.
He cast Love-Love Magic on the childhood friend who had always mocked him, yanked his hair, and bullied him, making her love him—love him more than anything.
He also cast Love-Love Magic on the beautiful female teacher whose classes had been terribly taught, making her his minion.
He cast Love-Love Magic on the nasty older boy who had refused to sell him mangoes, ordering him to sell mangoes to Markin alone, and for free.
He cast Love-Love Magic on Yasu-kun, a bad kid who was always scolded by his parents yet rubbed boogers on Markin whenever they met, and made him stick a smelly tree root into his nostrils.
His winning streak did not stop.
Markin's actions grew more and more outrageous as he wielded his genius-level intellect and incredible magic with utter impunity. Before long, he was casting Love-Love Magic on anyone and everyone, regardless of whether they had anything to do with his revenge.
And in just fifteen days, Markin completely conquered Eromanga Island, whose population numbered just under two thousand, and ascended the throne as its king!
Since Markin was king, he could ignore Eromanga Island's rule of monogamy.
Terrifyingly, Markin made his childhood friend, stepsister, female teacher, the most beautiful girl on the island, and a female tourist who had happened to be staying on the island and could no longer leave his wives, building an unprecedented grand harem that no one could imitate. It was an act that feared not even God.
Markin had cast Love-Love Magic on every resident of Eromanga Island. And because he was clever, he had every newborn brought to him immediately so he could cast the spell on them without fail. There were no gaps in his system of control.
Markin was a universal genius.
He not only ruled Eromanga Island but governed it perfectly.
That was tantamount to taking the whole world into his hands and manipulating it as he pleased.
No one but Markin, the Great King of the Ocean, could accomplish such a thing.
Wise King Markin loved wise deeds and hated fools.
Markin's policies were always wise.
Among the monsters that appeared on the island, he cast Love-Love Magic on the stronger ones and turned them into guardian deities.
He promoted the cultivation of medicinal herbs so that the island would not waste its limited supply of medicine.
He had excellent humans mate with one another just as excellent chickens were bred together, producing excellent humans.
He abolished the inefficient practice of burying corpses and ordered all bodies to be finely crushed and used as fertilizer or bait.
He invented a composite filtration system using ash, sand, and monster materials, providing the entire island with a stable, safe, abundant, and easy-to-use supply of fresh water.
He also used the power of wind and rivers to aggressively improve and automate the efficiency of labor.
When Markin's children all began displaying exceptional intellect, physical ability, and magical power without a single exception, Markin made every woman on the island his wife and diligently increased the number of excellent children.
As long as they were excellent, it did not matter whose children they were. But since his own children were the most excellent of all, there was nothing to be done. Markin worked tirelessly for decades to replace every islander with a high-spec long-eared person.
A shadow first appeared over Markin's perfect, smoothly prospering dynasty around the time the Markin Era passed its fortieth year.
The king's children had inherited his features. They were blond, blue-eyed, beautiful, and possessed high physical ability, magical power, and intelligence.
Their slow growth was a drawback, and from around the age of eight they began aging much more slowly, but that also meant they had long lifespans.
His eldest daughter, who had been born early on, became capable of having children at the age of thirty-five, so Markin had a talented young man brought over from Fiji Island despite the difficulties and married her to him. Before long, a grandchild generation would surely be born, and Eromanga Island was expected to grow ever richer and more prosperous.
However, even after five years, no child was born at all.
It was strange.
At first, he judged it to be an individual problem. He divorced his eldest daughter, who was unable to bear children, put her in the pet category, and placed his hopes on his second and third daughters. But that did not work either.
Wondering if the problem lay with the men, he even tried to have his daughters bear his own children, but that failed as well.
No matter how Markin wracked his brains or what he tried, no grandchildren were born.
As time passed, a rumor began to spread.
"The royal bloodline is cursed."
The rumor seemed plausible, and Markin grew anxious.
Was his blood really cursed?
Was it a cursed bloodline, incapable of producing grandchildren?
Could it be that, in his foolishness, he had spread a cursed bloodline throughout the island...?
He did not want to believe it, but no matter how much he investigated and experimented, he could reach no other conclusion.
The royal bloodline was afflicted by a curse that prevented grandchildren from being born.
By the sixtieth year of the Markin Era, ninety-five percent of the islanders had been replaced by Markin's children.
The replacement had progressed so far that they could no longer return to their former society of ordinary people.
For now, that was not a problem.
However, if no grandchild generation was born, then no matter how long-lived his children were, the islanders would die out after a thousand years when the succession between generations failed.
Markin's kingdom, which should have been eternal and imperishable, was fated to crumble beneath the merciless flow of time.
He did think of a policy to dispose of all the king's children and reset the island's environment, but he was reluctant to do so.
Markin had originally been an idiot, a useless piece of trash. He had been defective.
The children afflicted by the blood curse were defective as well, and looking at them often irritated him.
But disposing of those defective children felt like disposing of his former self, and the thought made him feel sick.
Reason whispered that he should dispose of the children with no future and start over from zero, but his miserable memories from long ago refused to let him do it.
He had come up with no good plan, but if he regularly sent boats outside the island to bring back new women and add them to his wives, he could at least avoid destruction from a future population decline.
It was unpleasant to depend on the outside world for the foundation of the island's continued survival and prosperity. But since there was no other way, it could not be helped.
Markin agonized over the matter at length, but in the end, he decided to take it slow.
The king and his children had long lifespans.
Long-term problems should be addressed over the long term.
There was no problem the genius Markin could not solve.
Markin was the proud ruler of Eromanga Island.
He would never lose to a blood curse!
And so, one day, while he was continuing his trial and error in an attempt to break the blood curse...
Three visitors arrived on Eromanga Island.
An intelligence officer reported to the palace that the three people who had landed on the island seemed to be gathering information about various things while remaining intensely alert.
When Markin looked at their portraits, the visitors were a woman with a sexy face, a woman with sexy breasts, and a man with a sexy ass.
What was more, all three possessed magical power on par with Markin's.
"Oh! Nice. Shall I make them all my wives?"
Markin said happily from his seat on the palace throne, and the intelligence officer nodded eagerly.
The problem of disparities in magical power was something Markin had been considering for some time.
Markin possessed an enormous amount of magical power. Was it possible that a curse arose because he had children with women whose magical power was pathetically weak by comparison? It was a rational suspicion.
Furthermore, according to the portraits and reports, the sexy-ass man was astonishingly a pure-blooded long-eared person like Markin himself, who had come from outside the island.
If Markin could somehow make this man bear one of his children, the result would be a long-eared child born from two magically powerful pure-blooded parents. There was a high chance the child would escape the curse. It was a rational prediction.
All three were exactly Markin's type, and it was a stroke of luck as though fish had leaped into his boat of their own accord.
He did not remember casting Love-Love Magic on the goddess of fortune, but perhaps he had done so and simply forgotten.
Markin, brimming with excitement, sent an envoy to invite the three visitors to the palace.
After about two hours, the visitors arrived, accompanied by several gawking onlookers.
A woman with a sexy face carrying a beautiful blue staff.
A woman with sexy breasts, huge in every respect, with horns growing from her head.
A blond, blue-eyed man with a sexy ass, looking as though Markin had aged himself by about ten years.
These were the three visitors.
Markin leaned forward from his throne and stared intently at the three people whose magical power rivaled his own. The three of them, in turn, stared intently at Markin and spoke.
"You are not Iruma. But you resemble Iruma after all—in both your appearance and your methods."
"You resemble Iruma in so many ways, but how should I put it... You're really worthy of the island's name!!"
"Ah, I'm sorry to say this when we've only just met, but looking at your face makes my skin crawl for some reason. I don't think I could deliver a fair judgment. Of course, we're nothing more than foreigners here, and it may be wrong for us to interfere in another country's customs. But this is..."
The sexy-ass man shifted his gaze from the king to the eldest daughter sitting beside the throne, then immediately looked away.
Markin had never allowed the eldest daughter, who had fallen into the pet category long ago, to wear clothes. Instead, he had required her to wear cat ears and a collar and serve the king as Nyan-chan.
It was a wonderful system Markin had created. Other countries' people might find it unusual.
Guessing that the handsome man flanked by two stunning beauties was the leader of the group, Markin addressed the sexy-ass man in a solemn voice.
"Welcome to Eromanga Island, honored guests. I welcome you."
"...Thank you for the welcome. I am Conrad Williams. I came to this island to meet you. These women are my friends."
"If possible, I would like us to have a peaceful conversation without using magic. Whatever the final outcome may be, I want to determine what kind of person you are first."
"Oh?"
Markin was intrigued by the sexy-ass man's words, his ass, and his clothes.
The visitor was special not only in person but in his attire as well.
"That outfit is a composite of monster materials and an unknown metal. The manufacturing process is a secret, I assume? But I can see through it. It must have high magical resistance. I take it this is a material and structure suited to the Age of Monsters, something that did not exist in the previous era. You melt thread spun from low-temperature-treated dragon sinew and immerse it in metal, don't you? If you're going to weave monster materials, that's the best method."
Beautiful, crystal-clear yet poisonous blue eyes like a bottomless swamp were fixed on the visitor.
Markin painstakingly gathered the information before his eyes, compared it against his own knowledge, analyzed it, and greedily pulled the truth toward himself.
"And yet I've never seen that luster before. I can't see any flaking of the metal. A new material with better compatibility with sinew fibers than gold or silver, hmm. Perhaps a new metal that did not originally exist on Earth, treated magically? Is that it? If such a new metal could be manufactured and obtained, then I would think it is not so much a new alloy infused with magical components as an existing pure metal processed by magic and..."
As Markin rested a hand on his chin and muttered as he assembled his thoughts, the horned woman went pale and nudged Conrad with her elbow.
"Conrad, this guy is bad news!!! He's not just a horny boy!!! He's the Iruma slot after all!!!"
"Hey. That's enough, isn't it? I'm sealing him. I don't want to give him any more time to think."
"It can't be helped. Do it. Sorry, King Markin. If you hold a grudge, hold it against me."
"...Hmm? Sealing? Me? What are you talking about? There is no ruler more excellent than me. What do you mean by sealing me?"
Markin had gone nearly eighty years without ever experiencing anyone defying him.
Since becoming a Transcendent, he had never fought anyone of equal or greater standing.
He had never left the island even once since birth and knew nothing of the world beyond it.
And although his intelligence had improved dramatically through mutation, he had originally been an idiot.
Only when the three visitors, who had carried an ominous air from the beginning, raised two staffs and a set of arm guards at him did Markin finally realize that they might insolently harm their king.
Markin was genuinely shocked, but that did not stop him from quickly diving behind the throne, grabbing his pet's head, and pulling it toward him as a shield.
"Merciful, aren't you? Life――――"
"Shatter――――"
"Know what lies beyond this instant" "There is no wise sage" "Embrace midnight"
"You, sink into the glacier――――"
A light projectile that flew around the throne and shield as though it possessed a will of its own struck the king in the jaw, interrupting his chant.
The children who tried to stop the visitors' barbarity all staggered unsteadily.
Ice shackles crawled over his hands and feet, and darkness swallowed Markin's vision.
Markin knew only his own magic.
He did not know the classic tactic of interrupting a long chant with a short one.
He did not know of monsters that could chant three spells simultaneously through three mouths.
He did not know about practically instant-death magic against which defense was meaningless.
He did not know about magic that required no chant.
Above all, because of the disastrous precedent set by the mage Iruma, he could not even imagine such an irrational situation as having his life targeted by three fully armed Transcendents of the highest caliber, with a flawless battle formation.
In short, Markin did not know the world.
In that instant of combat, Markin realized his fatal ignorance and simultaneously analyzed the information and considered countermeasures in his mind.
He needed knowledge, weapons, armor, experience, techniques, guards, vigilance, and strategy—all of it.
But it was already too late. That was partly because the visitors had acted specifically to make sure it would be too late for Markin.
In any case, the castle in the sand came crashing down.
"Sleep in the permafrost――――"
Magic released from the blue staff caught the king.
Even his final words froze in his throat, and Markin, King of Eromanga, was sealed in a cold deathlike sleep along with his throne.
The dynasty collapsed pathetically at the hands of emissaries from a foreign country.
The king's children in the throne room awoke from their dizziness and were bewildered to find that the magical marks of control that had been lodged in them since birth had vanished.
They exchanged words in a murmur, openly displaying their anxiety and confusion.
They had lived according to the king's words ever since they had become old enough to understand the world.
There had never been a moment when they had done otherwise.
The children knew no way of living except in obedience to the king, so even after the puppet magic was dispelled, they continued to follow the thoughts and lifestyle it had instilled in them.
"W-What should we do? Is the king dead!?"
"We have to break the glass and save him!"
The beautiful boys and girls, all of them young in appearance and closely resembling the king, swarmed around the block of ice imprisoning him.
The visitors watched them sorrowfully.
The ice created by Great Glacier Magic was not of ordinary strength.
Besides, it could not be melted without specialized magic.
How would the children of the cursed bloodline, who had lived under the king's rule, go on living after losing him?
Even if the king had been the root of all evil, it was the children who would suffer because of it.
To the world, he had been a dangerous person who had to be sealed away. But to the islanders, he had surely been a great father and king. Even if they had merely been made to keep believing that, it was still true to them.
The three visitors sank into dark thoughts as they considered the future of the children who had lost their twisted banner.
"But would saving the king actually benefit the island?"
However.
At that one muttered remark from one of the children, everyone came to a complete stop.
The situation had changed.
"Hey, Hiyo-chan!! You know what this means!!"
"Yes. Maybe it was all his own fault after all."
The king's brainwashing education had unquestionably corrupted the children to their very roots.
As a result, the children thought efficiently, exactly as the king had taught them.
"Hmm? We should be fine even without the king, shouldn't we...?"
"Honestly, we can run things ourselves, can't we?"
"Then there's no problem. Saving the king and antagonizing these people would probably be more harmful to the island."
"Then let's not save him."
"That's right. That's right."
"Meow."
"I think it's all right for you to speak human language now, Sis."
"Oh, really?"
"Yes. Under Markin's Law, when the owner dies, a pet is released from the pet category."
"That's right. That's right."
It was the blood of the efficiency-obsessed Markin, as well as the product of an education drilled into them from the moment they became aware of themselves.
The children swiftly reached a coldly rational decision and casually abandoned the king.
The king had been ruthless and demanded efficiency, so he was processed in the same manner himself.
He had brought it upon himself.
The eldest of the king's children—a girl who, until one minute earlier, had worn cat ears and imitated a cat on all fours—threw aside her costume, stood upright on two legs, and addressed the three Transcendents in a completely serious voice.
"Everyone, welcome to Eromanga Island. I would like to welcome you properly, but when a murder occurs on the main island, the holder of royal authority is responsible for conducting the trial. Since the former king has been murdered, royal authority has passed to me. Accordingly, I will be conducting your trial."
"However, even if I were to conduct a trial, I am ashamed to say that I do not believe the executive branch could carry out an appropriate punishment against you in accordance with the verdict. Therefore, as an exceptional measure, I will omit the pointless trial."
"Judging from your words and actions, it seems your purpose in coming to the island was to execute the king. Now that this has been accomplished, what do you seek from us? For our part, we would like to have a discussion that benefits both sides. What do you say?"
"...Uh, clothes, for starters."
The gentlemanly Conrad produced a tablecloth with Banquet Magic and draped it over the girl, who was standing proudly stark naked.
He waited for the girl to wrap herself in the tablecloth and catch her breath before replying politely and courteously.
"We have one request. We would like to remove the ice statue of your father from Eromanga Island and keep it under our supervision. If you absolutely cannot accept that, we will not force the matter, but in that case, we would like to station an observer from our country on Eromanga Island. Either way, I promise we will pay a fair price."
"Why we are doing this is a long story. I will sit down and explain our circumstances properly, so I would also like you to tell us what happened on Eromanga Island after your father's reign began."
Beside the hero who was earnestly repeating obscene words, the Blue Witch and the Witch of Hell once again expended considerable mental strength to keep strange expressions from showing on their faces.
The King of Eromanga had been safely sealed.
Eromanga Island seemed likely to become peaceful.