Kidnapped by Demons, Hired by the Demon King

It happened fast.

One moment, Saito was peacefully teaching Kina and Liora how to write a function that sorted ore types. The next, the sky split open with black smoke, and a group of flying shadow beasts swooped down from the clouds.

Before anyone could react, glowing chains wrapped around Saito, and a voice shouted, “We’ve secured the code caster! Return to the fortress!”

And just like that—poof—Saito vanished.

 Deep in Demon Territory

When he came to, Saito found himself in a dimly lit chamber carved into the walls of a black mountain. There were torches, bone pillars, and lava pits—everything you'd expect from a dramatic evil lair.

He was tied to a glowing crystal chair. A demon soldier with sharp teeth and a notebook stood nearby, squinting at him.

“You’re awake,” the demon said. “Good. Our commander wants to know how you make numbers float.”

Saito blinked. “Is this a kidnapping or a job interview?”

“Both.”

“Nice.”

A moment later, a new figure entered the chamber—tall, confident, and… surprisingly elegant.

She wore a black cloak, a crown of horns, and had glowing purple eyes. Her voice echoed with power, but her expression was calm.

“I am Velvara, Demon King of the Southern Wastes,” she said. “And I want you to teach my soldiers math.”

Saito stared.

“…What?”

“I heard rumors that you can make even beastfolk count correctly,” she said. “My army cannot even add their own salaries. Do you know how many forms I have to fill out? Endless. I need help.”

“You… kidnapped me for tutoring?”

She nodded. “Exactly. If you help me, I’ll make you my official ‘Demonic Mathematics Instructor.’ And also untie you.”

“…Alright, but I get a chalkboard.”

Demon Math 101

Later that day, Saito stood in front of a group of demon soldiers, ogres, batfolk, and skeletal accountants. His laptop floated beside him as he drew numbers in glowing air.

“Okay! Let’s start with multiplication,” he said. “If one potion costs 8 gold, and you want 5 potions, what’s the total?”

A demon minion scratched his horn. “Uhh… scream at the shopkeeper until he gives up?”

“No,” Saito said. “It’s 8 times 5 = 40.”

He turned to the board and typed:

def total_price(quantity, price_per_item):

return quantity * price_per_item

print("Total:", total_price(5, 8), "Gold")

Total: 40 Gold

The demons gasped. One of the ogres clapped.

“It did the thinking for us!” he cheered.

Velvara stood nearby, arms crossed, clearly amused.

“I thought it would be harder,” she said. “They seem quite invested.”

Saito grinned. “They’re not dumb. They’ve just never had a teacher who didn’t throw fireballs.”

“You are different,” she admitted. “And very strange.”

“Thanks,” he said. “I get that a lot.”

 Demon King Assistant Teacher?

The next day, Velvara surprised him by standing at the front of the class with a notepad and magical laser pointer.

“Today,” she declared, “we learn how to calculate mana consumption rates!”

Saito blinked. “You… want to help me teach?”

Velvara nodded. “If I understand it, I can make sure they don’t mess it up. Also, I’m good at intimidating students.”

Which was true. Every time a demon yawned or looked confused, Velvara gave them a stare so cold it could freeze lava. Attendance improved immediately.

She also picked up programming fast.

Saito showed her a sample:

def mana_usage(cast_count, mana_per_cast):

return cast_count * mana_per_cast

print("Total Mana Used:", mana_usage(3, 40))

Total Mana Used: 120

“I could use this for spell management,” she muttered. “Why didn’t anyone invent this sooner?”

Saito shrugged. “They were too busy inventing dramatic robes.”

Velvara smirked. “Point.”

Teaching Magic Through Math

Soon, the Demon King’s fortress had turned into a bizarre magic school.

Batfolk were making Excel-style scrolls. Fire mages were calculating flame intensity using power = mana × willpower. Even the castle chef asked Saito to build a calorie tracker.

Every night, Velvara and Saito reviewed lesson plans in her chamber.

“You’re not afraid of me,” she said one evening, handing him tea.

“Why would I be?” he asked. “You’re the most polite kidnapper I’ve ever met.”

She laughed softly. “It’s refreshing. Most people shake when I say hello.”

“You say hello with a thunderclap and ten-foot wingspan,” he said. “You might want to ease up on that.”

“…Fair.”

A Letter from the Outside

One morning, while reviewing a chart on potion inventory, a demon messenger ran in with a scroll.

“It’s from the catgirl!” he shouted. “From the village!”

Saito opened it immediately. It was written in shaky but adorable handwriting.

Sensei! You disappeared!! Liora and I have been looking everywhere! I hope you're okay. If you're kidnapped, blink twice! —Kina (and Liora)

He laughed.

“Your apprentices miss you?” Velvara asked.

“Yeah,” Saito said. “They’re the reason I started teaching. They deserve to know where I am.”

She nodded. “Then I have a proposal.”

A Demon-Human Alliance of Education

That afternoon, Velvara made an official royal announcement:

“The Demon Army will form an education alliance with Saito Minoru. We will create the Underworld Academy of Logic & Magical Computing. Any beastfolk, demons, elves, or ogres may attend.”

Saito added, “And there will be snacks!”

The room erupted in cheers.

“Also,” Velvara added, “I will serve as assistant head teacher. You may call me ‘Vice Sensei.’”

“…Is that a real title?” Saito whispered.

“It is now,” she said proudly.

As the banners were raised and demon soldiers practiced multiplication tables, Saito looked up at the sky from the tower.

From enemy to ally. From prisoner to professor. This world truly had a weird sense of humor.

But for now?

He had a school to run—and a Demon King to train