The Crown Prince In Hiding

The Academy stood at the center of the five-pointed cross where all five human kingdoms met.

TheArtheris Institute.

A prestigious academic institution that gathered the brightest minds from across the five kingdoms.

And the crown prince’s fiancée happened to be an alumna.

“There it is, Freya.”

He pointed up.

“That’s our place!”

“What!? There’s an entrance exam!?”

“Yes,” the administrative staff replied.

“But the registration fee is ridiculous!”

“Yes.”

“…”

The young man was speechless as he stared at the Artheris Institute’s application form.

It wasn’t about the money—but to a prince, it was about whether the fee made sense. And this... didn’t.

“This is outrageous! You can’t just do this! This is daylight robbery! Half the tuition just to apply!? That’s insane!”

“Our Artheris Prestige program has upheld the highest standards for over a thousand years. Our reputation stretches across continents and is synonymous with leadership. If you have a problem with that, please feel free to apply elsewhere.”

At the motel.

“Shall I blow them up, Your Highness? You could easily do it.”

“Three hundred thousand years…”

“I was kidding.”

Freya flopped onto the motel bed while the crown prince sat beside her, staring bitterly at the receipt labeled ‘application fee for admission suitability assessment’—for two applicants: himself and Freya.

“Sigh… if my little brother saw this, he’d have a meltdown.”

The boy let out a long breath and collapsed next to her.

“You know what?” she began.

“Hmm?”

“The average Artheris student is half our age.”

“Whoa, really? So they enroll at, what, fifteen? What’s the rush?”

“It means humans get to train longer, Your Highness.”

“…You’ve got a point. Hmm. Might be worth copying.”

“How would that work? We barely have any births per year—we could count them on one hand.”

“That’s not the point. We can all train regardless.”

“No matter how hard they train, they’ll never match the power of us Diablos. One of us could wipe out ten of them.”

“That kind of thinking is exactly why we lose to their magic.”

This was Diablo’s greatest weakness.

Physically, they were unmatched. But magically… utterly hopeless.

It was like nature’s way of balancing out their overwhelming strength—they were abysmal at using magic. They could barely manage simple, common spells that even human children could cast.

Which meant, in war, Diablos were naturally weak against Mages, Priests, and especially Light Magic users or Holy Knights.

“So why do you need to apply at all? Why not storm into the Light Kingdom and just ask where that woman is? How hard could it be?”

“That’d ruin everything… The moment I show my real body here, it’s game over.”

Diablos didn’t mess with human territories. They stayed separate—unless for trade.

If the identity of the crown prince were exposed… it would be catastrophic. Disastrous. It would raise countless questions and signal a breach of territorial treaties.

Even if the real reason was simply to search for Casca Saint-Maximin, no one would buy it. Human leaders wouldn’t stand by—they’d accuse the Diablo Kingdom of espionage, treaty violations, and more.

“This isn’t some sneaky infiltration. If I get exposed, our entire house falls. Our reputation will be destroyed.”

“So why pretend to be a student?”

“Blending in at a prestigious academy hits the sweet spot. Not as flashy as a knight, not as obscure as a peasant. That’s why I chose to enroll.”

“Not because it’s her alma mater?”

“…Maybe a little.”

“So it is personal.”

“Two hundred and forty thousand years…”

“But seriously, I can’t believe you convinced the Emperor to approve this. I still can’t believe they let us both go. How’d you manage that?”

“Uh…”

When Casca vanished from Diablo, she left a letter on the prince’s bed.

Fury,

I’ve lived in Diablo for ten years now.

But you’ve never once visited my kingdom. Have you even stepped outside unless it was for war? I can’t recall.

Aren’t you curious what the outside world is like?

Let’s play a game.

I challenge you to come find me on the human side. One year. That’s all you get. In the meantime, I’ve got some unfinished business to deal with.

You’ll find me—if you’re not too much of a coward hiding in your hole. Hehe.

Love,

Maximin

She disappeared without warning. No fights, no signs.

But Fury knew her well.

The letter was clearly daring him to explore the world—as a human.

She used to tell him stories about the human kingdoms—places he’d never seen except during wartime. He didn’t know how humans really lived.

He closed his eyes, and memories came rushing back.

Casca Saint-Maximin—his fiancée.

“The era of peace is upon us,” she said once, lying beside him under the stars.

“You should try walking through a human city sometime.”

“You’ve told me all about it. That’s enough.”

“Imagination can’t beat the real thing.”

“My imagination’s pretty vivid.”

“Can you imagine what it’ll feel like when we part ways?”

“…Even imagination has its limits.”

“Then all the more reason to go.”

“Here, you’re accepted because of your strength. Casca, you’re the only human allowed to come and go in Diablo.”

“But I still miss home, Fury.”

She picked a tuft of green grass and let it drift on the wind.

“Diablo may feel like where I was born, and everyone’s kind to me… but it’s not the same as my real home.”

“You’re going back?”

“And I want to bring you with me.”

“That breaks the treaty.”

“Who said I’d take you like this?”

“Even if I looked better, I wouldn’t go.”

“In ten years, we’ll end up across that ocean anyway… Might as well get used to human cities early.”

“Message received. Please allow processing.”

“You sure? I might just disappear as a surprise.”

Casca’s letter now lay in the center of Diablo’s royal council.

BAM!

Fury slammed the table, panic written all over his face.

“She’s serious!!!”

“Oh really?”

Fury had one younger brother and one younger sister.

“Oh dear… how tragic.”

“Everyone! This is serious! She’s gone!”

“Don’t act so shocked. As if there’s anything in this world that could kill her.”

That was his little sister, Fiorentina.

“I saw her leave at 5 a.m.”

“What!? And no one told me!?”

“I ordered them not to.”

That was his younger brother, Everton.

“I just felt like it. I was annoyed, that’s all.”

“Wait, don’t tell me—she conspired with you guys!?”

“Three ancient Paladin tomes for my collection. Fair trade, don’t you think?”

“I’m not surprised at you, Everton… but you too!?”

“Max asked me. She’s my sister. I love her more than everyone else combined.”

In Fury’s mind, he saw Casca grinning mockingly, galloping away on horseback, luggage in tow.

“You guys deserve to be thrown out a window. Casca’s not here to protect you from me anymore.”

CrackCrack

His siblings clung to each other, trembling, as their older brother rolled his neck menacingly.

“Brother, we couldn’t possibly take you in a fight. Please spare us.”

“Then I’ll have to go after her myself.”

Right then, after Fury declared it—

His father, the supreme ruler of Diablo, didn’t object. Instead, he said:

“Go ahead. Sounds fun.”

“Come on, Father! Don’t encourage her nonsense—huh?”

Fury turned his head.

“Wait… seriously?”

“You’ve got nothing left to prove to me, Fury.”

The Demon King looked into his son’s eyes.

“You’ve done so much for me. It would be cruel not to reward you for it.”

“How can you help?”

“We can turn you into a human.”

Thus—

Crown Prince Fury could now switch between human and demon form at will, thanks to advanced magical engineering—a secret of the Diablo Kingdom.

And before he departed—

It was too risky to go alone.

Even if the chance of something happening to him was low, traveling with someone else was safer.

That’s why he chose Freya as his royal bodyguard.

Her true form was a 1.9-meter-tall demon with a mushroom-shaped head, humanoid female torso and lips, venomous bladed arms, and lower body like a mermaid with no tail—ending in tentacled feet.

From a distance… she looked exactly like a jellyfish with 2 arms and legs.

Freya had grown up alongside Fury. Though she looked unassuming, in wartime she could wipe a city off the map with her poisonous mist.

She passed all criteria easily and underwent the ritual to gain human form.

However, she’d never gotten along with Maximin—and probably never would—even though all of Diablo loved her.

The reason? Her deep bond with Fury, forged long before he met his fiancée.

“That woman must’ve hexed you…”

The wolf-cut girl rolled over to stare at the boy with her beautiful green eyes.

“She made you risk everything just to come here… She’s forcing you into a world you don’t understand.”

“Then you’re the only one who can resist her magic. You’re stronger than me, stronger than my dad, stronger than my mom. Clap clap clap.”

“She stole you from me!”

“I respect Casca’s way!”

“What a stupid tradition… Why can’t we mate with others too? What’s the logic? I don’t get it.”

“I don’t really get it either… But if it hurts Casca, I won’t do it.”

“Good! I want to see that woman heartbroken.”

“At least you’re honest… Probably the only person in the country who could openly insult the queen if that day comes.”

“Is it even possible? A human queen? It’s never happened before.”

“Then I’ll give up the throne. Simple as that.”

“You’ll pass it to Prince Everton? Would he even want it? He’s better suited to be a merchant.”

“If he doesn’t want it, then Fiorentina can take it. Demon Queen. End of story.”

“You can’t toss the throne around like it’s trash!”

“Speaking of… did you fill out your application yet? We’re submitting it tomorrow.”

She squirmed against him—

Then suddenly placed her hand on his pants and reached inside.

“Isn’t it cute? Human anatomy… Looks like a plant we have back home. Oh! It’s growing!”

“Hey! Freya! Don’t squeeze—it hurts!”

“Looks like this is Your Highness’s weak spot.”

“But… it feels weirdly good…”

“Is that even possible? Those two feelings are opposites.”

“Why is human anatomy so complicated…”

“Maybe if we mated in human form, we’d understand.”

“No!”

“She said we couldn’t mate in true form. She didn’t say anything about this one, did she?”

“She wouldn’t like it…”

“Then don’t tell her.”

“What’s the point in hiding it? I’d have to answer if she asked.”

“Just once…”

“Don’t you remember? I don’t want to think about the day she walked in on us mid-mating. Diablo nearly collapsed. She almost chopped your head off. Did you forget?”

“What did you tell her?”

“The truth. We mated. Everyone does—Father, Mother, even Everton. Fiorentina’s got a whole harem. I’m the only one who’s stayed with just you.”

“Exactly! That’s the point! We’re not like humans. If we lay three eggs in a lifetime, that’s already miraculous. I mean, look at us—we’ve been a pair forever. Then suddenly she shows up and NUH-UH! No more mating. What!? She’s forcing human norms onto a Diablo! Is that fair? She stole my job! My entire role! I hate her! I hate her so much!”

“Humans reproduce more, so mating means more to them. It’s probably a sacred thing. People break up or even kill over it.”

“Ridiculous.”

“Think of it this way. Rice—in some countries it’s just food. But in certain mountain tribes, rice is sacred. You can’t eat it freely. That’s the closest analogy I’ve got.”

“Fucking ridiculous.”

“Respect my wife!”

“Nonsense.”

Seeing she wouldn’t back off—

Fury tried another approach.

“Hey… I just realized. They’re a hundred times more fertile than us. We better hold off. If you got pregnant, you’d be immobile for nine months.”

“Oh! I totally forgot. That’d ruin everything.” She withdrew her hand from his pants.

“Exactly.”

“Pathetic. We give birth and sprint by sundown.”

“Don’t compare dragons to rabbits… Once we see Casca again, we can ask her. She might allow it if it’s this form.”

“Hmph. Someone that selfish? Fat chance, Your Highness.”

“Then guess what I want right now?”

“What?”

“Go fill out that application!”

“Ughhh!!!!”