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The abandoned warehouse was quieter than any battlefield they’d ever stood on.
No gunshots.
No blood.
Just a whiteboard.
Yu Ijin stared at it like it had personally insulted him.
“Explain it again,” he said flatly, arms crossed over his scarred chest, school blazer tossed aside. His grey hair fell over eyes that were currently open—focused, sharp, dangerous.
The enemy on the board read:
Quadratic Functions.
008 stood in front of it with a marker like it was a tactical knife.
“You’re overthinking it,” 008 sighed, adjusting his glasses. “It’s just patterns. Numbers behave predictably.”
Ijin’s eyes narrowed slightly.
“…They don’t.”
From the corner, 006 snorted. “Yeah, they do. You just multiply and stuff.”
008 turned slowly. “Multiply what.”
“…Everything?”
A vein popped in 008’s temple.
005 was sitting on a crate, staring at the board like it might explode.
“Why is there an ‘x’?” 005 demanded. “If you don’t know the number, just find it.”
“That’s what we’re doing,” 008 snapped.
“No,” 018 cut in, arms folded. “You said x equals something. So you already know it.”
“I said we’re solving for x!”
“Then solve it,” 016 muttered.
Silence.
Even Ijin blinked at that.
008 took a deep breath. “Okay. Ijin. Focus.”
Ijin stood straighter instinctively.
“When you see ax² + bx + c = 0—”
“Why is it zero?” 004 interrupted from the floor, where he was lying on his back eating Korean fried chicken out of a box.
“Because that’s how equations work.”
004 chewed. “I don’t trust it.”
002, who had been silent in the shadows the entire time, finally spoke.
“Continue.”
One word.
Calm. Commanding.
Everyone straightened.
Even 008 swallowed and nodded.
“Alright. The quadratic formula is—”
He turned and wrote it carefully.
x=2a−b±b2−4ac
The room went dead silent.
Ijin stared at it.
His face remained expressionless.
But his eyes?
Dangerous.
“…That looks illegal,” 032 muttered from behind a laptop.
006 squinted. “Why is there a square root? We’re not building anything.”
005 rubbed his forehead. “What’s that weird plus-minus thing? Pick one.”
“You don’t pick one!” 008 shouted.
004 raised a chicken wing. “I vote minus.”
“We’re not voting!”
002 looked at the formula.
“…Explain the battlefield application.”
008 blinked. “Battlefield— what?”
“If it has no practical application,” 002 said evenly, “it’s useless.”
Ijin nodded once in agreement.
008 looked like he might pass out.
“Okay. Fine. Hypothetically,” 008 said through gritted teeth. “You’re calculating trajectory.”
All eyes snapped to him.
Ijin leaned forward slightly.
Now you had his attention.
“Like… a thrown knife?” Ijin asked quietly.
“Yes! Exactly! The arc is a parabola. That’s a quadratic function.”
The room shifted.
That made sense.
005 leaned in. 018 sat up straighter. Even 004 stopped chewing.
008 quickly drew a curved arc on the board.
“This is the path.”
Ijin studied it intensely, as if mapping wind direction in his head.
“So if I know the angle,” he murmured, thinking, “and force… I can predict the drop.”
“Yes!” 008 nearly cried in relief. “Exactly!”
There was a pause.
Then 006 raised his hand lazily.
“…What if you just throw it harder?”
008 froze.
016 nodded seriously. “Or get closer.”
005 added, “Or shoot.”
018: “Or don’t miss.”
The silence that followed was catastrophic.
008 dropped the marker.
“You’re all impossible.”
Ijin stared at the equation again.
His eyes slowly closed.
Which meant one thing.
He was frustrated.
“…I can dismantle a sniper nest from 800 meters,” he said quietly. “But this doesn’t make sense.”
There was no anger in his voice.
Just genuine confusion.
And for a moment, something softened in the room.
004 sat up.
006 leaned back.
005 looked away.
They had all survived hell together.
But math?
Math was cruel.
002 stepped forward.
He looked at the board.
Then at Ijin.
“You don’t need to understand everything alone,” he said calmly.
Simple.
Direct.
Ijin’s eyes opened again, a faint red tint flickering in embarrassment rather than anger.
“…I know.”
From the back, 032 slowly raised his laptop.
“I have a solution.”
Everyone turned.
008 narrowed his eyes. “What did you do.”
032 grinned.
On his screen was the school’s teacher login portal.
“I may or may not have accessed the math teacher’s PC.”
There was a collective pause.
“May or may not?” 006 smirked.
“Definitely did,” 032 corrected proudly. “I have tomorrow’s test answers.”
The warehouse went silent.
Then—
005: “Send it.”
018: “Immediately.”
016: “For academic research.”
004: “If this works I’m buying chicken for everyone.”
Even Ijin hesitated.
002 looked at 032.
“…Delete it.”
The room froze.
“What?!” everyone shouted.
002’s gaze didn’t waver.
“We survive because we adapt.”
His eyes shifted to Ijin.
“And he doesn’t run from battles.”
Ijin met his gaze.
There it was again.
That unspoken understanding.
A battlefield wasn’t always made of concrete and bullets.
Sometimes it was a classroom.
Sometimes it was numbers.
Ijin exhaled slowly.
“…Explain it again,” he said to 008.
008 blinked.
“You’re serious?”
A small pause.
“…Yes.”
005 groaned loudly.
006 flopped back dramatically. “I’m going to war again.”
004 shoved chicken into his mouth aggressively. “I hate math.”
032 sighed and closed the laptop. “Fine. But if we fail, I’m hacking the government.”
018 muttered, “That escalated fast.”
008 picked up the marker again.
“Okay. From the top.”
Ijin stepped closer to the board.
Shoulders squared.
Eyes focused.
Like he was preparing for combat.
And around him, the Numbers stayed.
Complaining.
Arguing.
Confused.
But staying.
Because no matter how terrifying the world was—
No matter how many scars lined Ijin’s skin—
This was their family now.
And if their strongest soldier could face down math like an enemy…
Then they’d stand beside him.
Even if they all ended up mad at algebra by the end of it.